Please exit the app and open it again. Then check if the problem persists.
In order to force Hexatech to close you should follow up the steps below:
1-Press the Home button two times quickly. You'll see small previews of your recently used apps.
2-Swipe left to find hexatech application
3-Swipe up on the app's preview to close it.
If the issue persists please contact our support team for further assistance.