App frozen
Apple phone - Come out of the app then click on the Home/Touch ID sensor button twice. You will then see all of your recent apps. To kill them just swipe them off the screen.
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Android phone - Press "Recent apps" icon on the right. This will bring up the recent apps. To kill them either swipe them left or right off the screen.
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You can then reopen the app and log in again to start using it.
Many thanks
The MyTeamSafe Support Team