I'm wanting to get a fitness device that claims to communicate over BLE and which claims to work on IOS and Android devices -- I'm going to ask them which devices but Google does not indicate what sub-sections of the BT4 spec they have as part of the Nexus 4. I further realize that the Android OS is not officially supporting a BLE solution at this time but some device mfg's have some drivers available (broadcom IIRC) that can be loaded possibly.. Anyone ever try one of these types of devices with your Nexus 4 to see if it will work? I do not yet have an N4 so I can't test directly..