For the Android app:
To be able to use your app in the best conditions you need to have the Android OS version 5.x or superior.
For the iPhone app:
The iPhone app requires the iPhone OS version 9.x or superior.
For the Android app:
To be able to use your app in the best conditions you need to have the Android OS version 5.x or superior.
For the iPhone app:
The iPhone app requires the iPhone OS version 9.x or superior.