In the Settings app, go to Accessibility > Touch > Back Tap and choose one of two options: double tap or triple tap. You should see a list of actions you can run by tapping the back of your iPhone, ...
I tried the Topdon JS3000 out of the box, but the real test came six months later when I had to dig it out again.
I tried the Topdon JS3000 out of the box, but the real test came six months later when I had to dig it out again.