I had the same SUPER annoying issue. Every time you unlock your device, the zmodo app take priority and opens up. Even if i’m opening a notification for another app, there is Zmodo.
I always just used the Home button to close it out before, but I did find that using the back button until the app closes itself will work, but I don’t think it’s a perfect solution because I’ve encountered it a few times even when backing all the way out of the app.
I just wish the app developers would fix it.