Staying Connected: How to Download and Run Facebook on iOS 12.5.7
Performance Tips for Facebook on iOS 12.5.7
Since this is an older hardware + older app combo, use these settings to keep Facebook running fast:
Since the standard "Get" button in the App Store might trigger an "Incompatible" error, 1. The "Purchased History" Workaround
To download Facebook on a device running iOS 12.5.7 (such as an iPhone 5S, 6, or 6 Plus), you cannot install the latest version directly from the App Store because Facebook now requires iOS 13.4 or later.
However, you can still install an older compatible version:
She couldn’t afford a new phone. Not since the factory closed.