Not all phones have Gorilla Glass displays. If your phone does not then yes, you want a screen protector. I have Ghost Armor on my phone and my wife's phone. Ghost Armor has kiosks in some malls and they will install it for you. I liked the feel of the screen of the Ghost Armor material over the Zagg Invisible Shield. If you want the Zagg, Best Buy will install it for $15 plus the material. The Ghost Armor has a lifetime warranty and the kiosk will install it for $5 (and if they no longer have one for your phone at the kiosk, you order it yourself under warranty from the company and then take it to have it installed). You are touching the screen a lot so even if you don't drop it you run the risk of marking the screen up without a screen protector.