The privilege of being first to market with any tech means you're the only choice for people who want what you're offering. Exogear's iPhone 4 battery case is in this lucky position. The good news? It's actually well done.
We don't know if your iPhone 4's battery life will really be doubled by the Exolife battery case, but at least we know that the case is slim, light, and will give your gadget a bit of a power boost.