If you open the app and it is stuck on a screen, that is solid black or solid white, try force closing your app.
1. The quickest way to force close the app is from the home screen. Start by viewing all your running apps. Depending on your phone model the exact method may differ
- Swipe up from the bottom of the screen
- Tap the small square icon on the bottom of the screen
- Press the physical button on the bottom of your phone that looks like two overlapping rectangles (you may not see it unless you press in the area next to the Home button)
- On Samsung Galaxy devices: press the Recent Apps button (to the left of the Home button)
2. Once you see all your running apps, swipe left or right until you see the Gemstone HUB.
3. Swipe up on the app you want to close. Alternatively, some apps also have a small X button in the top right that can be pressed.