One of the signature features of Jolla's first smartphone is The Other Half -- an intelligent phone back that uses NFC to automatically customize the phone's software. Early owners haven't really had a chance to try the feature for themselves, but that's changing now that Jolla is selling The Other Half covers through its website. Paying €29 ($40) will get you an Aloe- or Keira Black-colored shell, either of which changes the system sounds and wallpaper to reflect a cohesive theme. And if you're not happy with Jolla's designs, you can make your own -- the company has released a developer kit that includes the 3D printer file, software instructions and tech specs that you'll need to get cracking. It currently takes two to three weeks for The Other Half units to ship to European customers, but anyone who's unwilling to wait can grab the do-it-yourself tools right away.