Tools like XAP Extractor or WPUtil allow you to mount the emulator .vhd files and rip the system XAPs directly. These are the most stable apps in existence.
Several hubs currently host large collections of archived Windows Phone software: windows phone xap archive full
As Microsoft officially discontinued support for the OS, apps began vanishing from the official store. This sparked several grassroots efforts to build a "full" archive: Tools like XAP Extractor or WPUtil allow you
Notable uploads:
Depending on your phone's OS version, use one of these methods: and install Windows Phone XAP archives
Below is a useful guide on how to find, download, and install Windows Phone XAP archives, specifically focusing on "homebrew" and legacy app preservation.