Otterbox Defender Series
You know Otterbox as the company that produces those insanely protective smartphone cases that will guard your device from pretty much anything short of a bullet. It's still the same company, but now in addition to keeping your phone safe, it also wants to keep it powered up. The upcoming Defender Series features a 1450mAh battery that can effectively double the life of your iPhone. The best part, however, is the accompanying app that keeps an eye on your battery so the case doesn't overcharge, shortening its lifespan. Smart and safe.