You may need to forcibly stop the app every once in a while in case it's no longer working properly. Doing so will stop all processes and allow you to restart it properly.
To do so, perform the following steps:
- Go to Settings on your smartphone.
- Go to Apps.
- Tap the Withings Health Mate™ app.
- Tap Force stop.
- Tap OK.
You can now restart the app.