AssistiveTouch helps you use iPhone if you have difficulty touching the screen or pressing the buttons.

You can use a pointer to click icons on your screen that you might otherwise tap, or use it to navigate the AssistiveTouch menu. If you want to use an input button to show and hide the menu, go to Settings > Accessibility > Touch > AssistiveTouch

Use AssistiveTouch on your iPhone, iPad, or iPod touch You can use AssistiveTouch to adjust volume, lock your screen, use multi-finger gestures, restart your device, or replace pressing buttons with just a tap.