For tracking your correct posture:
1) Choose the alarm and sensor settings (see Menu)
2) Save correct (initial) posture angles: tap button and place (fix) this Android device during next 10 seconds on your body (pocket, phone case) at the correct comfort posture.
3) Start the tracking service
App dialog can be closed now, info is in the notification area.
Warning: Android sleep is blocked, be noted higher battery discharge.
Internet permission is for Media-player that plays sound alerts.
Paid app version has max tilt angles to be controlled up to 75 degrees.
This app can be useful for Android users being operated on the backbone, with intervertebral hernia, scoliosis.
App may be useful instead of separate sensors controlling the posture, like Lumo Lift.