PopSlate Case
Your iPhone is great communications tool — but it's mostly only useful if the screen is on, meaning that you're drawing battery power like crazy even if all you're doing is checking and re-checking a list. The PopSlate Case aims to fix this by adding a four-inch ePaper display to the back of your phone. Syncing with a companion app over Bluetooth, its monochrome screen uses little to no battery power, making it ideal for displaying maps, to-do lists, speaking notes, recipes, electronic boarding passes, and other items that don't need interaction to be useful, saving you valuable battery life while making your phone that much more useful.