Kickstarter recently. The bluetooth-enabled device features a D-pad on its surface, potentially solving the "pesky touchscreen D-pad" crisis plaguing some mobile games, such as platforming titles.
A $45 pledge will put one of these Android and (soon to be) iOS-compatible rings on your finger, along with a small collection of games developed around the peripheral. Pledging $55 grants developers early access to the device's API. Ringbow will go into production if the project meets its $100k goal by July 22.