iOS
Jailbreaks
Dopamine - Jailbreak for iOS devices running up to iOS 15.4.1, allowing users to install third-party apps outside of the App Store.
palera1n - Jailbreak for iOS devices using the A8-A11 chips (iPhone 6 to iPhone X) on iOS 15.0-16.5 using the checkm8 exploit.
Third-Party App Stores
AltStore - Alternative app store for non-jailbroken iOS devices. Requires a computer that is avaiable weekly due to the expiration limit.
TrollStore - Permasigned jailed app that can permanently sign any IPA, only supported up to iOS 15.6 beta 5.
Sideloadly - Simple installer of ipa files for non-jailbroken iOS devices. Requires a computer.
YouTube Clients
uYouPlus - iOS YouTube client including YouPiP, iSponsorBlock, video downloading, removed ads and many more features.
YouTubeRebornPlus - Fork of YouTube Reborn for non-jailbroken devices with even more features.
Discord Clients
Vendetta - Cross-platform plugin-based Discord client mod.
Enmity - Plugin-based Discord mod for iOS.