files specifically for versions as old as iOS 3.x up to iOS 7.x. You can browse the Legacy iOS App Archive
An (iOS App Store Package) is the proprietary archive format for iOS apps. For iOS 7.1.2, standard IPAs are specific because: ipa files for ios 712 top
Mtmdev hosts a massive FTP-like index of IPAs sorted by iOS version. Navigate to /IPAs/iOS 7.x/ . Their top downloads for 7.1.2 include: files specifically for versions as old as iOS 3