It would be nice if "Other Half" covers connects to a physical USB 3 interface on the phone that support host mode and plug-n-play, rather than NFC/blue tooth/wireless.

A "Other half" with usb hub that you can plugin a 4 TB hard disk, keyboard, mouse, bar code scanner, RF id reader, or what ever USB devices you my have.

A "Other half" maybe something that allows us to plug in a standard SDXC card with the feature(s), instead of carrying around several "Other half" covers that just offers us 1 extra feature. Just carry around a bunch of SDXC cards will be much easier and more practical. Other half may even support multiple SDXC slots. This makes it easy for developers to come up with SD cards instead of a full back cover.

Other Half/SD Card options I am thinking of.

• A car key that allows you to start/stop the car.
• A key that recognizes when I am away and locks my PC.
• A secure payment method
• A key that provides extra security for emails, etc.