Update: All these coupon codes have expired.
For the iPhone 7, use code
AK7062BG and get it in these colors:
For the Samsung Galaxy S8, get it in these colors:
The Galaxy S8 version of this case is brand new because the phone is pretty new, too, so this is definitely the best deal for that version. The iPhone 7 version floats around $10 most of the time, although Anker is known for their coupon codes so it has probably been lower before.