Skip the Zagg. I fooled with that SP for month s, it's grippy and terrible with stylus use.
Take a look at the Powersupport screen protector It is very nice here's a review it works the same on iPad as iPhone.
I recommend the one I've been using for a couple of months called ArmorSuit from Amazon. If you want a solid protector that doesn't affect your device's visibility, it's all yours.