AltStore update brings new sources, new emulators, and virtual machines to iOS with no jailbreak required
Riley Testut's AltStore is perhaps the most popular alternative method of loading apps on devices running iOS. While its built-in app store is relatively small, a major update (available today) adds multiple trusted sources to the service alongside other new features.
Version 1.5 of AltStore, available to everyone today, adds three new "trusted sources" to the AltStore app. These include Flyinghead, OatmealDome's AltStore Source, and the UTM Repository. These are simply repositories of non-Apple-approved iOS apps that have met AltStore's safety standards.
The addition of these sources makes it easy to install emulators for three retro systems: Sega's Dreamcast (via Flycast) and Nintendo's Gamecube and Wii (via DolphiniOS). Coupled with Testut's own Delta emulator, retro gamers can now enjoy games from every major Nintendo platform (excluding the 3DS, Wii U, and Switch) from apps available via the AltStore app.
The new sources also bring UTM to the AltStore. This app allows users to load virtual machines on their iDevice, so now it's relatively straightforward to run an instance of Linux or Windows on an iPad or iPhone.
Users can still install their own iOS apps via AltStore, provided they have the .ipa files for the apps of their choice.
The new update, which was released in compliment to an update for the associate AltServer service, also brings just-in-time (JIT) compilation to apps installed via AltStore. JIT compilation allows a machine to compile source code into machine code in real-time, rather than when an application is loaded. In essence, JIT should improve performance for more demanding loads like the demands of virtual machines and high-end emulators.
Currently, JIT on iOS is only available for side-loaded apps and seems to be intended for developers to debug their apps. However, AltStore can now use AltJIT, which is a workaround that allows sideloaded apps to use JIT to improve performance.
All this means that more demanding and complex apps, like the aforementioned UTM for virtual machines and DolphiniOS emulator, should run much smoother and be usable. Testut has stated before that JIT could allow the Delta emulator to emulate more complex gaming systems, like the PlayStation 2 and Wii. DolphiniOS can be configured to use AltJIT to improve performance.
It's important to note that AltStore does not require users to jailbreak their iDevice. It uses a workaround involving free developer accounts to sideload apps. Normally, apps that aren't available in Apple's official App Store must be sideloaded. However, for most people (i.e., those without a paid developer account), these apps will expire after seven days. AltStore and AltServer use workarounds to refresh these apps prior to their seven-day time limit, allowing users to keep them installed.
AltStore can be installed on any device running iOS via AltServer, which currently requires a computer running Windows or macOS. Some features, including AltJIT, require iOS 14 or later.