Youtube 1.2.1 Ipa Download [2021] May 2026

Introduction

The rise of social media and video-sharing platforms has revolutionized the way we consume and interact with online content. YouTube, in particular, has become an indispensable part of our digital lives, offering a vast array of videos on various topics, from entertainment and education to music and vlogging. While YouTube is readily available on Android devices, iOS users often face limitations when it comes to accessing the platform's full features. This is where the YouTube 1.2.1 IPA download comes in – a modified version of the official YouTube app that offers additional features and functionality.

What is IPA Download?

IPA (iOS App Store Package) is a file format used to distribute and install iOS applications. When an app is downloaded from the App Store, it is packaged in an IPA file, which can be installed on an iOS device. However, sometimes developers or third-party sources offer modified or hacked versions of popular apps, which can be downloaded as IPA files. These files can be installed on an iOS device using third-party tools or apps, allowing users to access features that are not available in the official App Store version.

Features of YouTube 1.2.1 IPA Download

The YouTube 1.2.1 IPA download offers several features that are not available in the official YouTube app on iOS devices. Some of these features include:

• Background playback: The official YouTube app on iOS devices does not allow background playback of videos. However, the YouTube 1.2.1 IPA download enables this feature, allowing users to listen to videos while using other apps or when their device is locked.
• Dark mode: The IPA version of YouTube offers a dark mode, which can help reduce eye strain and battery consumption, especially in low-light environments.
• Video downloading: With the YouTube 1.2.1 IPA download, users can download videos directly to their device, making it possible to watch them offline.
• Ad-free experience: The modified app also offers an ad-free experience, which can be a significant advantage for users who are tired of watching ads before and during videos.

Risks and Precautions

While the YouTube 1.2.1 IPA download offers several exciting features, it is essential to note that downloading and installing IPA files from third-party sources can pose risks to iOS devices. Some of these risks include:

• Jailbreaking: To install IPA files, users may need to jailbreak their device, which can void its warranty and make it vulnerable to security threats.
• Malware and viruses: Third-party IPA files can contain malware or viruses, which can compromise device security and user data.

Conclusion

The YouTube 1.2.1 IPA download offers several features that are not available in the official YouTube app on iOS devices. However, users should be cautious when downloading and installing IPA files from third-party sources, as they can pose risks to device security and user data. If you're looking to enhance your YouTube experience on iOS, it's essential to weigh the benefits and risks and consider alternative options, such as using the official YouTube app or exploring other video-sharing platforms.

End of Essay

The download for YouTube version 1.2.1 format is primarily sought by users of legacy iOS devices (such as those running iOS 6 or below) who wish to experience the original user interface or maintain compatibility with older hardware. Finding the YouTube 1.2.1 IPA

Official sources like the Apple App Store no longer host this version. You can find archived copies on community-driven platforms: Internet Archive

: A reliable repository for legacy software. You can find collections like the All YouTube IPAs archive which lists various historic versions. Reddit Communities

YouTube 1.2.1 IPA Download: A Trip Down Memory Lane For the modern smartphone user, the idea of "YouTube 1.2.1" feels like a relic from a different era. Today, we are accustomed to 4K streaming, Shorts, and complex algorithms. However, for enthusiasts of retro tech and vintage iOS devices, hunting down a YouTube 1.2.1 IPA download is about more than just watching videos—it’s about digital preservation.

In this article, we’ll explore why this specific version matters, how the IPA file format works, and what you need to know if you're trying to get classic YouTube running on an old-school iPhone or iPad. What is an IPA File?

Before diving into version 1.2.1, it’s important to understand the format. An IPA (iOS App Store Package) file is the archive format used to distribute apps for Apple devices. Think of it like an .EXE for Windows or an .APK for Android.

When you download an IPA, you are essentially holding the entire app’s code, assets, and icons in a compressed folder. While modern users simply tap "Get" in the App Store, "sideloading" IPAs is the only way to install versions of apps that Apple has long since removed from their servers. The Significance of YouTube 1.2.1

YouTube 1.2.1 dates back to the early days of the standalone YouTube app. To understand its place in history, we have to remember the "YouTube Divorce" of 2012.

The Built-in Era: From 2007 to 2012, YouTube was a native app built by Apple into iOS (then called iPhone OS). It featured the famous "retro TV" icon.

The Standalone Shift: With the release of iOS 6, Apple removed the built-in app. Google then released their own "YouTube" app on the App Store.

The Early Versions: Version 1.2.1 represents one of the earliest iterations of Google’s independent vision for YouTube on mobile, long before the UI became cluttered with modern features. Why Users Look for YouTube 1.2.1 Today

Most people looking for a YouTube 1.2.1 IPA download fall into one of two camps: 1. Legacy Device Support

If you own an iPhone 3G, iPhone 3GS, or an original iPad running iOS 5 or 6, the modern YouTube app simply won't install. It requires much newer hardware and software. Finding a legacy IPA is often the only way to get the app icon back on the home screen. 2. The "Old Web" Aesthetic

There is a growing community of "r/LegacyiOS" enthusiasts who prefer the skeuomorphic design (realistic textures like leather and glass) of early iOS. Version 1.2.1 captures that aesthetic perfectly. How to Install a Legacy IPA (The Reality Check)

If you find a download for the YouTube 1.2.1 IPA, installing it isn't as simple as clicking a button. Here is what the process usually involves:

Jailbreaking: Most vintage devices must be jailbroken to bypass Apple's "signing" requirements for apps.

Sideloading Tools: Users often use tools like Sideloadly or older versions of iTunes to move the file from a computer to the device.

The API Problem: This is the biggest hurdle. Even if you successfully install the 1.2.1 IPA, it likely won't work. YouTube has changed its Data API (the way the app talks to the servers) many times since 2012. Opening the app today usually results in a "Connection Error." Is There a Fix for the "Connection Error"?

For those dedicated to making it work, the community has developed "tweaks" (like TubeFixer) that redirect the app’s requests to custom servers, allowing these ancient versions of YouTube to actually load video data again. Security Warning

When searching for YouTube 1.2.1 IPA downloads, be extremely cautious. Only use reputable community archives like MTN's App Archive or the Internet Archive (Wayback Machine). Downloading IPAs from random "cracked app" websites can expose your computer or device to malware. Conclusion

The YouTube 1.2.1 IPA is a fascinating piece of mobile history. While it’s no longer practical for everyday use, it remains a "holy grail" for collectors trying to restore their old iPhones to their former glory. It reminds us of a simpler time in the mobile landscape—when apps were smaller, designs were glossier, and the mobile video revolution was just beginning.

Are you trying to revive a specific vintage Apple device, or are you just looking for a way to browse classic app designs?

Bringing the Classics Back: How to Download YouTube 1.2.1 IPA Youtube 1.2.1 Ipa Download

If you’re holding onto a vintage iOS device or just miss the early days of mobile video, you’ve likely searched for YouTube 1.2.1 IPA. This specific version, released in late 2012, is a piece of digital history that supports devices running iOS 5.0 or later.

While modern apps are packed with features, they often leave older hardware behind. Here is everything you need to know about finding and installing this classic version safely. Why Version 1.2.1?

Released shortly after Apple removed the built-in "classic" YouTube app in iOS 6, version 1.2.1 was one of Google’s first standalone offerings for the App Store.

Legacy Support: It is one of the few versions compatible with older software like iOS 5.

Classic UI: It features the iconic early-2010s interface, offering a nostalgic browsing experience.

Basic Essentials: It still includes core features like subscriptions, trending videos, and personal recommendations. Where to Download

Finding a legitimate IPA file is the most critical step. Avoid untrusted third-party sites that may bundle malware.

Internet Archive: Highly recommended for historical preservation. You can find archived versions of YouTube IPAs here.

Community Forums: Trusted legacy communities on Reddit's r/LegacyJailbreak often share verified links for older versions. How to Install (Step-by-Step)

Since this app is no longer on the App Store, you must "sideload" it using a computer.

Download the IPA: Save the YouTube 1.2.1 IPA file to your Windows or Mac computer. Use a Sideloading Tool:

Sideloadly: A popular choice that works on Windows and Mac. You’ll need to connect your device and log in with your Apple ID to "sign" the app.

AltStore: Great for slightly newer "legacy" devices, though it requires refreshing every 7 days unless you have a developer account.

Trust the App: Once installed, go to Settings > General > Profiles & Device Management (or "VPN & Device Management") on your iOS device and "Trust" your Apple ID to allow the app to run. Important Considerations

API Limitations: Because Google has retired older versions of the YouTube Data API, some features in version 1.2.1 (like comments or even video playback) may require community-made tweaks like TubeRepair to function today.

Security: Always scan downloaded files and be aware that using extremely old software can expose your device to older, unpatched security risks.

Install IPA files on any IOS devices | Signed | Working (100%)

YouTube 1.2.1 for iOS is a legacy application originally released in December 2012. It was designed to support iOS 5.0 or later, making it a primary choice for users of "vintage" hardware like the iPhone 3GS, iPhone 4, or early iPad models who wish to restore native app functionality.  Overview of YouTube 1.2.1 

This version represents the first wave of standalone YouTube apps after Apple removed the pre-installed version in iOS 6. It features the classic "skeuomorphic" design language of the early 2010s and includes basic features like: 

Subscription Management: Access to your subscribed channels.

Recommendations: Personal video suggestions based on history. Trending: Discovery of popular global content.  Download and Installation Requirements 

Because this app is no longer available on the official App Store, users must utilize an IPA (iOS App Archive) file and side-loading tools. 

Obtain the IPA: The file can be found in community-driven archives such as the Internet Archive's iOS IPA Collection.

Sideloading Tools: You will need a computer and third-party software like iMazing or Sideloadly to transfer the file to your device.

Jailbreaking (Optional but Recommended): On older versions of iOS, having a jailbroken device with "AppSync Unified" installed simplifies the process of running unsigned or legacy IPA files.  Vital Usage Warning 

Modern YouTube APIs have changed significantly since 2012. Simply installing the 1.2.1 IPA may result in a "Connection Error" or an empty feed. To make this version functional today, users often need to: 

Edit the Info.plist: Manually change the version string (e.g., to "15.0") inside the app package to bypass server-side blocks.

Use Tweak Fixes: Install community-made tweaks like "TubeFixer" from Cydia to restore server connectivity.  Safety and Verification 

Always exercise caution when downloading software from third-party sources. It is recommended to scan downloaded IPA files with antivirus software before attempting installation on your device.  Youtube 1.2.1 Ipa Download - Facebook

YouTube version 1.2.1 for iOS, originally released in December 2012, was one of the earliest standalone versions of the app after it was no longer pre-installed as a system app in iOS 6. One notable feature of this specific version was:

Expanded Subscription Access: It allowed users to fully access and manage their subscriptions directly from a dedicated sidebar, along with browsing personal recommendations and discovering trending videos. This version was designed to support iOS 5.0 or later. Youtube 1.2.1 Ipa Download - Facebook

2. Jailbreak and Tinkering Communities

Jailbreakers often strip down their devices to improve speed and battery life. Modern YouTube apps consume massive resources. The 1.2.1 version is incredibly lightweight, measured in mere megabytes instead of hundreds. Some developers also reverse-engineer old IPAs to study early iOS design patterns.

Conclusion

Downloading and installing YouTube 1.2.1 as an IPA carries legal and security risks unless you control the binary source (your own backup) and re-sign/install it using trusted credentials and tools. Safer alternatives include the App Store, mobile web, or approved third-party apps. Introduction The rise of social media and video-sharing

Related search terms (you can use these for further research):

• YouTube 1.2.1 IPA download
• iOS IPA sideloading safety
• how to re-sign IPA with Xcode

YouTube 1.2.1 IPA is a highly sought-after file for enthusiasts of "retro-tech" and legacy iOS devices. This specific version, released around 2012–2013, represents a pivotal moment in mobile history: the transition from the built-in Apple-designed YouTube app to Google’s standalone version. Why Users Seek YouTube 1.2.1

While modern versions of YouTube offer 4K streaming and Shorts, version 1.2.1 is prized for several unique reasons: Classic iOS Aesthetic

: It features the iconic "skeuomorphic" design—glossy buttons, linen textures, and realistic shadows—that defined the Steve Jobs era of iOS 5 and iOS 6. Legacy Device Support

: It is often the last functional version for older hardware like the iPhone 3GS , or the original , which cannot run modern iOS versions. Performance

: On older processors, this version runs significantly faster than modern, "bloated" apps, provided the backend connection still functions. The Challenge of Legacy IPAs

Downloading and installing a decade-old IPA file isn't as simple as clicking "install." Users typically face two major hurdles: Server-Side Obsolescence

: Google has long since retired the APIs used by version 1.2.1. Without custom community patches (like

), the app will usually open to a "Connection Error" or "Update Required" screen. Sideloading Requirements

: To install an IPA file outside the App Store, users generally need a jailbroken device or tools like Sideloadly , along with a valid Apple ID to sign the app. Where to Find It

The community-driven preservation of these files happens primarily on specialized archives: MTN (MobiTog Network) : A hub for legacy mobile software. Internet Archive (Archive.org)

: Often hosts complete collections of "Cracked" or "Original" IPAs for historical preservation. Reddit (r/LegacyJailbreak)

: The primary community for troubleshooting and finding links to verified, safe legacy files. Safety Warning

When searching for "YouTube 1.2.1 IPA download," be wary of third-party sites promising "one-click installs." These can often bundle malware or adware. Always stick to reputable community archives and never provide your primary Apple ID password to untrusted sideloading software. Are you looking to install this on a specific legacy device , or are you interested in the history of the app's design

Feature Idea: "YouTube Legacy Mode" (Hypothetical Browser Extension / Shortcut)

Purpose:
Allow users to experience a simpler, faster, data-friendly version of YouTube reminiscent of older app versions (like 1.2.1) — without downloading unofficial IPAs.

How it works:

• A Safari extension or iOS shortcut that loads YouTube’s mobile website with a custom stylesheet and script.
• Disables modern bloat (Shorts, heavy animations, autoplay, large thumbnails).
• Enables a clean, minimal interface similar to YouTube’s early iOS app.
• Reduces data usage and improves battery life on older devices.

Key features:

• No ads (using system-wide content blockers like AdGuard).
• Background audio playback (via browser workaround).
• No need to jailbreak or sideload.

Implementation:

• Build as a free, open-source Userscript (usable with Userscripts app on iOS) or Shortcut that rewrites YouTube’s mobile page.
• Host on GitHub for transparency.

If you'd like, I can provide a template for a Safari extension that recreates a lightweight YouTube interface legally — or explain how to sideload safely for development/testing purposes only. Let me know.

YouTube 1.2.1 IPA: Everything You Need to Know YouTube 1.2.1 is a legacy version of the official YouTube application for iOS, originally released in December 2012. It is primarily used today by collectors and enthusiasts of vintage Apple hardware to restore functionality to older devices like the iPhone 3GS, iPhone 4, and early iPads. Key Specifications Version: 1.2.1.5201 Release Date: December 2012 Minimum iOS Version: iOS 5.0 Architecture: 32-bit (Not 64-bit compatible) File Size: Approximately 13.5 MB to 15.5 MB Why Users Download YouTube 1.2.1

For owners of "legacy" devices, this specific IPA file is one of the few versions compatible with iOS 5.0 and later. While modern versions of YouTube require iOS 16.0 or newer, the 1.2.1 version offers:

Subscription Access: Capability to view your subscribed channels.

Personal Recommendations: Browsing tailored video suggestions. Trending Videos: Discovering what is popular globally. Where to Download

Since this version is no longer available on the Apple App Store, users typically turn to community-driven digital libraries.

Internet Archive (Archive.org): Hosts various archived versions of the YouTube IPA, including 1.2.1 for iOS 5.0.

Legacy Communities: Sites like Reddit's r/LegacyJailbreak often provide links to mirrors or patched versions that restore login functionality. Installation and Troubleshooting

Installing an IPA from a third-party source requires a computer and specialized software. How to fix YouTube on old iOS! (2025 Tutorial)

YouTube 1.2.1 IPA is a legacy version of the YouTube iOS application, originally released in December 2012

. It is primarily sought after by enthusiasts and collectors using older hardware, as it is one of the few versions compatible with Key Features of Version 1.2.1 Classic UI

: Features the original, non-Material Design interface popular in the early 2010s. Legacy Compatibility : Supports older devices like the iPhone 3GS, iPhone 4 that cannot run modern iOS versions. Core Functionality

: Includes access to subscriptions, personal recommendations, and trending videos. How to Download and Install

Because this version is no longer available on the Apple App Store, users typically source it from community archives and sideload it. Locate the IPA : Legacy files are often hosted on the Internet Archive or shared within community forums like

Step-by-Step: How to Install YouTube 1.2.1 IPA (If You Have the Right Hardware)

Note: This guide assumes you have a jailbroken iPhone 2G or 3G. Background playback : The official YouTube app on

1. Locate the file: Obtain the YouTube 1.2.1.ipa from a trusted archive (like Archive.org).
2. Install AppSync Unified: On your jailbroken device, open Cydia and install "AppSync Unified" from Karen's repo. This allows you to install unsigned or old IPAs.
3. Use a sideloading tool: On your computer, use iPhoneBrowser, iFunBox, or 3uTools. Connect your iPhone via USB.
4. Install the IPA: In the tool, find the "Install App" button, select your IPA file, and wait for it to transfer.
5. Set up a Proxy: To actually stream videos, you must follow a guide on r/LegacyJailbreak to set up a local proxy (like "Tubi") that reroutes the old app to modern YouTube.

The Technical Hurdles: It’s Not Simple

Before you rush to find a download link, you need to understand the technical reality of installing an IPA from 2009 onto hardware in 2025.

Closing image: a device with a familiar face

Imagine an aging phone lit up in a dim room, its screen showing the rounded icon and uncluttered interface of YouTube 1.2.1. A user scrolls through a subscription list that loads without algorithmic suggestion, clicking on a video and watching without autoplay dragging them elsewhere. There is comfort in that control, a memory of earlier internet tempos — slower, more intentional, more human.

YouTube 1.2.1.ipa is less about a file and more about the longing it represents: for simpler interfaces, for archives that let us revisit the past, and for the complicated, sometimes risky rituals people will follow to reclaim small fragments of digital history.

Searching for "YouTube 1.2.1 IPA" primarily yields results for much later versions (like v10.0 and above) or modern modified clients like uYou+. Historical versions of the YouTube app, such as the original YouTube 1.0 IPA, can occasionally be found on digital preservation sites like the Internet Archive. The Ghost in the OS

The cursor blinked, a rhythmic heartbeat in the dark room. Leo’s fingers hovered over the mechanical keyboard, hesitant. He wasn’t looking for the latest 4K features or high-bitrate streaming; he was looking for a ghost.

On his desk sat a pristine iPhone 2G, its silver back catching the moonlight. It was a relic of 2007, a time when the "Tube" was a pre-installed icon of an old-fashioned television. But that icon had been dead for years, a victim of expired APIs and digital progress.

He hit "Enter." The screen of his modern laptop filled with the directory of a forgotten server. There it was: YouTube_1.2.1.ipa.

Leo initiated the transfer. A progress bar crawled across the screen, a bridge between two decades. When the phone finally chirped, he tapped the screen. The old TV icon flickered to life. For a second, the screen stayed white, and then—magic. The simple, low-resolution thumbnails of a simpler era began to populate.

He didn't need the algorithm to tell him what to watch. He just wanted to see the world through a 3.5-inch window one more time, back when the internet felt like a small, cozy library instead of a roaring ocean. He pressed play on a pixelated video of a cat, smiled, and for a moment, time stood perfectly still.

YouTube 1.0 IPA : Google : Free Download, Borrow, and Streaming

YouTube 1.0 IPA : Google : Free Download, Borrow, and Streaming : Internet Archive. Internet Archive asdfzxcvbn/uYouPlusExtra: uYou+ is a modified ... - GitHub

Searching for "YouTube 1.2.1 IPA" typically leads you toward the "Legacy Jailbreak" community—a group of enthusiasts dedicated to keeping older Apple devices like the iPhone 4 or iPad 1 functional in the modern age What is YouTube 1.2.1? Released around December 2012

, version 1.2.1 is one of the earliest standalone YouTube apps for iOS. Historical Context

: Prior to iOS 6, YouTube was a built-in "system app" developed by Apple. Version 1.2.1 was part of Google's first wave of independent App Store releases after Apple removed the native YouTube app.

: It features the classic "skeuomorphic" design—glossy buttons, linen textures, and the old-school sidebar menu. Compatibility : It was designed to run on iOS 5.0 or later Where to Find the IPA

Because this version is no longer on the official App Store, users turn to community archives: The Internet Archive

: A reliable source for various historical YouTube IPA versions, including early 1.x releases. Reddit (r/LegacyJailbreak)

: The primary hub for users sharing links to decrypted IPAs and troubleshooting vintage hardware. The Catch: Why it Might Not "Just Work"

Downloading the IPA is only half the battle. Because YouTube's modern servers (API) have changed drastically since 2012, simply installing the app usually results in a "Connection Error". Required Tweaks

: To make it functional, legacy users often use jailbreak tweaks like YouTubeFor6 to redirect the app to working data streams. Installation

: You cannot install these via standard iTunes today. Most users use tools like Sideloadly on newer firmware, or iFunBox/Cydia on older devices. Modern Alternatives for IPA Sideloading

If you aren't looking for a "retro" experience but rather enhanced features (like ad-blocking) on a modern iPhone, the community has moved on to patched versions such as: uYouEnhanced YTLitePlus

: These are modern IPAs that include premium-like features and are regularly updated for iOS 15–18. Are you trying to get this running on a specific older device , or are you looking for a modern tweaked version of YouTube? Youtube 1.2.1 Ipa Download - Facebook

YouTube 1.2.1 iPA is an older version of YouTube app that was released in December 2012, and it supports iOS 5.0 or later. Install IPA Files on iPhone FOREVER! No Revokes, No Expiry

Warning: Before proceeding, please note that downloading IPA files from unofficial sources can pose risks to your device's security. Be cautious and ensure you're downloading from a trusted source.

What is YouTube 1.2.1 IPA?

YouTube 1.2.1 IPA is an older version of the YouTube app for iOS devices. The IPA file is an archive file used by iOS devices to install apps.

How to Download YouTube 1.2.1 IPA:

To download YouTube 1.2.1 IPA, you'll need to use a third-party app store or a website that hosts IPA files. Here are a few options:

1. AppPure: AppPure is a popular third-party app store that offers a wide range of IPA files, including older versions of apps like YouTube. You can download the AppPure app from their official website, then search for YouTube 1.2.1 IPA within the app.
2. IPA Library: IPA Library is another website that hosts IPA files. You can search for YouTube 1.2.1 IPA on their website and download it directly.
3. Cydia: If you have a jailbroken iOS device, you can use Cydia to download YouTube 1.2.1 IPA.

Installation Instructions:

Once you've downloaded the YouTube 1.2.1 IPA file, you'll need to install it on your iOS device. Here are the steps:

1. Using Cydia Impactor: If you're not jailbroken, you can use Cydia Impactor to install the IPA file. Download Cydia Impactor from the official website, then connect your iOS device to your computer. Follow the on-screen instructions to install the IPA file.
2. Using AltStore: AltStore is another popular tool for installing IPA files. Download AltStore from the official website, then follow the on-screen instructions to install the YouTube 1.2.1 IPA file.

Caution:

• Using older app versions might expose you to security vulnerabilities.
• Make sure to only download IPA files from trusted sources.

By following the steps outlined above, you should be able to download and install YouTube 1.2.1 IPA on your iOS device. I hope that helps.

You're looking for information on downloading YouTube 1.2.1 IPA. The IPA file format is commonly associated with iOS applications, suggesting you're trying to install an older version of the YouTube app on an iOS device.

How to install an IPA safely (high-level)

• Preferred: Re-download source from App Store (if possible) or use your iTunes/App Store app library backups.
• Developer/Xcode method (recommended for developers): Use Xcode to install signed builds onto a device you control.
• Sideload tools: Use reputable sideloading tools that require you to sign with your own Apple ID; avoid installers requiring enterprise certificates.
• Always revoke or remove any enterprise certificates and configuration profiles you didn’t explicitly install.

Common Sources (Proceed with Extreme Caution)

• Archive.org: The Internet Archive is the most reputable source for vintage software. You can find "iPhone OS 1.0 - 3.1.3 IPA bundles" here. This is the safest option, as files are scanned for viruses (though IPA viruses are rare on macOS/Windows).
• iPhone Wiki (The iPhone Wiki): A resource for developers and jailbreakers. They do not host IPAs directly for copyright reasons but often provide links to decrypted IPAs dumped by the community.
• Reddit (r/LegacyJailbreak): The community subreddit for old iOS devices. Users share Google Drive or Dropbox links to IPAs. While community-vetted, you still rely on individual uploaders.
• Questionable Third-Party Sites: Websites ending in .xyz, .cc, or obscure forums are common in search results. Avoid these. They frequently serve malware (fake .exe files disguised as IPAs) or use aggressive adware.