Lost 19k b/c app/site doesn't log you out

I know somebody that lost 19k b/c the mobile app, none of Tvate really, logs out when you shut the app/site down. It stays logged in. So… his kids got ahold of his iPad and emptied his 19k acct. Probably be a good idea to do something about that. I noticed that long time ago too. I assumed when it close it it will log out.