Unfortunately, quite a lot Android devices out there do not support gathering accelerometric data (sleep tracking) with screen-off. This is duo to a bug which is on 100% of devices with Android version 1.6 to 2.3.4, on many +2.3.5 device and even on several devices with +4.0. We are doing an automated detection of whether […]
Probably your phone has been detected as unable to track with screen off (please check Application settings → Misc → Screen off tracking). Please see Troubleshooting for more details.