Arguably the most widely-used emulator is now available on iOS, iPadOS, and tvOS. Retroarch, a multisystem emulation frontend, landed on the App Store this week. The app is free and open-source.
Retroarch is technically an emulation frontend, not an emulator. In other words, Retroarch is a tool to organize a variety of emulators (referred to as "cores). However, it is colloquially referred to as an emulator.
The version of Retroarch on the official App Store provides 78 cores to emulate different consoles, handhelds, and machines. These range from popular consoles like the Super Nintendo Entertainment System (SNES), PlayStation (PSX), and Sega Genesis/Megadrive to more obscure systems like the Fairchild Channel F, Mattel Intellivision, and Sharp X68000.
Retroarch is also packed with a bunch of features, including save states, netplay for multiplayer, retro achievements, and shaders (which can alter the resolution or graphics style of games). It also supports MFi controllers (like the 8BitDo Micro, currently available on Amazon for $22.49).
The app is free to download and doesn't collect data from users. Gamers will need to provide their own game files, and some cores will require users to provide BIOS files for the respective consoles.
Retroarch is currently sitting at the #2 spot on the App Store in the Entertainment category. It is available for iPhones and iPods running iOS 14.2 or later, iPads running iPadOS 14.2 or later, Apple TVs running tvOS 11.0 or later, and Apple Vision headsets running visionOS 1.0 or later.
You can download Retroarch here.