Apps should not sign you out. Websites shouldn’t, too.
Once I’m logged in, I’m logged in. Indefinitely. Until my laptop dies. Even then, I’ll probably migrate all my browser sessions to a new machine, and I expect services to continue to recognizing me.
We have the technology (notice how services can reliably remember your account’s name but somehow “forget” you authentication).
There’s no good reason to sign people out periodically. It doesn't increase security. If it does anything, it forces people to choose simpler passwords. It also makes our lives miserable.
Please. Stop the madness. I don’t want to log into things for the rest of my life.