A lot of issues can be solved easily by simply restarting your device. If you are having problems, try this first.
If you are using an iPhone, iPad or iPod:
- Press and hold the Sleep/Wake button on top of the device for a few seconds, until a red slider appears.
- Then slide the slider.
- Wait till the device is shut down.
- Then press and hold the Sleep/Wake button until the Apple logo appears.
- After that start the app again.
If you are using an Android device:
- Press and hold the Sleep/Wake button for a few seconds until a menu appears.
- Select Power Off or Shutdown.
- Wait a minute until the device has shut down.
- Start the device by pressing the Sleep/Wake button.
- Start the app again.