Klear Cut via Amazon offers its Klear Cut Screen Protector 6-Pack for Apple iPhone 6S for $5.48. Coupon code "YVW2O48V" makes it free. With 50 cents for shipping, that's $20 off list and the lowest total price we could find. They are scratch-resistant.

Also available is the Klear Cut Screen Protector 6-Pack for Apple iPhone 6S Plus for $5.48. Coupon code "757YDW4D" makes it free. With 50 cents for shipping, that's $20 off list and another price low.