Use the old boy scout method and turn your phone, tablet into a sun compass. Just point the sun symbol to the sun and the compass rose points north. You can add a target angle to easily follow the direction you want.
- Drag the compass to turn it freely
- Touch the compass to make it jump to the 4 major directions
- Use a two finger drag to turn the target
- See whether its day or night
- The compass is not affected by magnetic anomalies