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It depends, from cracking or scratching?

Personally, I use PowerSupport on the front of my iPhone. I have their anti-glare, which I have used for the last 2 years or so. The Apple Store used to sell them, I have no idea why they stopped.
 
I just got my skinomi tech skin for my 5s and love it, easy and perfect alinement everytime, i have it on my ipad mini as well.
 
Tempered glass screen protector from a generic Chinese company. Looks like it's part of the screen... in fact, 60% of the time, it looks good all the time. :)
 
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