The TopoCharger is an odd little device, but it could be useful for some. It’s an iPhone GPS case. What? Yes. A GPS-less GPS that comes with on-board storage for maps, and a big fat battery pack so you can use your iPhone in GPS mode without killing its own battery dead. If you’re wondering why you’d bother with this instead of just using a regular battery case, then keep wondering, because I have no idea. Yet. Let’s check it out.