Count the rakahs without touching the screen

Place the iPhone on the prayer rug, screen up. Each time you go down into sujud, the proximity sensor registers it and the counter moves.

The words on the screen are turned toward you, so they read correctly while your forehead is near the phone. You do not unlock the phone or look for a button in the middle of the prayer.

It is a counter, not a teacher of the prayer. You still follow the rakahs you intended. The phone only keeps the number.