: Reported to still function surprisingly well.
When you open the App Store on iOS 9.3.5 today, most modern apps simply display the dreaded gray "Unable to Download" button or demand iOS 13+. However, Apple built a clever (if hidden) system: . If you previously downloaded an app, the store will offer the final version that worked with iOS 9.
: This popular sheet music reader has legacy versions that run on older iPads. How to Install Unsupported Apps on iOS 9.3.5