iPhone tip #4: enable Back Tap
Go to Settings / Accessibility
Tap 'Touch'
Scroll down and tap 'Back Tap'
Now tap 'Single Tap' or 'Double Tap' and then choose an action or app to open
When you tap the back of your iPhone 2 or 3 times the action will occur. This is a very clever feature, but be aware that Double Tap can be accidentally activated quite easily.
Sometimes you just need to know how to use a feature or do something new without loads of adverts or pop-ups getting in the way. I hope this tip was useful to you.