Bolting a second screen onto the back of your phone might sound bonkers, but Oaxis’ upcoming iPhone 7 Plus case makes a lot of sense: it’s rocking the same kind of display tech you’d find on a Kindle e-reader, so it sips on battery rather than guzzling it down like an addict. Throw in Bluetooth and you’ve got an always-on display for notifications, distraction-free reading and customisable widgets. And yes, it’ll help you frame those all-important selfies too. The waterproof case will keep your phone safe from the elements, and only adds a paltry 4mm of extra bulk. The Kickstarter campaign is live right now, so you can slap down $89 and be first in line for when the finished version arrives next month.