Apparently, with the recent Amber update for Windows phone 8, Nokia Lumia 520 will support BT-LE (Bluetooth low enery or bluetooth smart). Other smartphones (Android and Windows) may support BT-LE.
Has any one tried using the 520 (or other smartphones) as a bike computer using BT-LE compatible HRM and cadence/speed sensors? What bike software did you use?
If you did, do post your experiences here.