A screen protector adds an extra layer of safety to your phone screen. It may not prevent your phone's screen from cracking up. There can be may causes for the screen to crack.

A screen protector only provides an extra protection in case of direct contact.

Good phone screen protectors are scratch resistant , but clear. They make fingerprints easy to wipe off. They are easy to insyall and some even come with cleaing tools.

The best screen protector for iPhone 7, 6s, and 6: TechMatte amFilm Tempered Glass Screen Protector (good price, scratch resistant, easy to install)

The best screen protector for iPhone 7 Plus, 6s Plus, and 6 Plus: TechMatte amFilm Tempered Glass Screen Protector (same quality as top model but for larger screens)

The second best screen protector for iPhone 7, 6s, and 6: Yootech Tempered Glass Screen Protector

The best screen protector for iPhone 7 Plus, 6s Plus, and 6 Plus: Yootech Tempered Glass Screen Protector