There is a similar product, Sony Ericsson LiveView, which can be worn as a wristwatch and paired with an Android phone: http://www.sonyericsson.com/cws/products/accessories/overvie...

Retails for EUR 39.50.

I do not own one so cannot say anything about how well it works -- just came across it randomly yesterday when buying something online. If the client is Android-based it is almost certain the protocol can be easily reverse engineered to make it hackable from other paired devices.