We’re using an Android tablet in landscape mode as a permanent display showing all our cameras, it looks great now that we’ve added a 4th camera to fill out the blank spot 
Usually in the morning though we’d find that the app no longer runs. The tablet is set to never-sleep mode, it’s possible that it might have rebooted by itself but I’m not sure how to check. I’m just wondering if the app itself would just quit after running for a while. Occasionally, I’ve seen it crash and there’s a prompt asking if we want to restart the app. Maybe it crashed and the prompt just times out and leaves us at the home screen?
What app version are you running ? The most recent app version 2.3.69 Update fixed the timeout issue for me
2.3.69 is what I have