: For users with jailbroken devices, tools like Checkmate, Store! (available via Cydia) can sometimes force the App Store to offer older versions that were previously hidden. You can also attempt to sideload specific .ipa files using tools like Sideloadly on a computer, though finding a working legacy .ipa is difficult and may pose security risks. Critical Compatibility Notes
If you previously had Facebook installed on this device when it was on a newer iOS, you can extract the IPA from an iTunes/Finder backup using iMazing, then sideload it back using Impactor. facebook ipa for ios 9.3.5