There are many applications that can use iPhone's motion sensors, accelerometers and compass. So when any of them stops working properly, it will make life frustrating. Fortunately, these can be recalibrated regularly by opening your location service. If the location service is not ready, you will follow the following steps.
- Open Settings
- Scroll down and tap Privacy
- Tap Location Services
- Swipe the Location Services toggle switch into the green On position
- Scroll and down and tap System Services
- Swipe the Compass Calibration toggle switch into the green On position
- Swipe the Motion Calibration & Distance toggle switch into the green On position
Users of older iOS versions may need to recalibrate the compass and motion sensors by opening the compass and playing a mini-game that requires you to roll a red ball around the circle.
In addition, there is another way of calibrating these tools. For some applications, you can go to their "settings" and directly calibrate the related tools (as shown by the gyroscope in the figure below).