What Apple iOS versions does ForeFlight support?

Minimum iOS Version: 

The current minimum iOS version supported by ForeFlight Mobile version 12.4 (May 2020) and later is iOS 12, though some app features require iOS 13. Devices that are not running at least iOS 12 will not be able to update the app beyond version 12.1.

Older iPads that cannot be updated beyond iOS 9.3.5 can still continue to use ForeFlight Mobile 9.6.