1byone via Amazon offers its iPhone 6 / 6s 3100mAh Battery Charging Case in Gold (pictured), Black with two color frames, Black with seven color frames, or White with seven color frames for $34.99. Coupon code "NLFFDQLM" drops it to $19.99. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $6.29.) It features a battery level LED readout, ability to sync without removal of the case, and a purported extra 14 hours of talk time. It ships with a microUSB cable. Deal ends January 20.