Wow! Right now you can score this Maxboost Fusion Snap-on iPhone 5S/5 Case (Fit Fusion Battery Case for iPhone 5S/5) for FREE after coupon code! Amazon has it regularly priced at $19.95, however it is on sale for just $9.95 AND when you use coupon code 2LV69DHY at checkout the price drops to $0. Shipping is FREE, which means you just got an iPhone 5 case completely FREE!
It has been confirmed that this is working on the mint and blue cases, however I am not sure about the other colors.
(Thanks Coupon Pro!)