Lucky Patcher is forbidden to be discussed here given what most people use it for.
I'm not aware of anything that will hide root on a per app basis, you can only 'hide' it on a system-wide basis in SuperSu (uncheck Enable Superuser in settings), run the app you want to run, then unhide root (recheck Enable Superuser in settings; you may need to reboot to re-enable root).
This will work for some apps, but it depends on what the app actually checks for when it checks for root. If it only queries if SuperSu/similar is enabled, then that will solve your problem.
If it's important enough to cause you grief if it's lost, back it up. No excuses
Trolling for thanks is lame
Does Samsung's auto-brightness implementation crap drive you to self-harm ? A solution !
Failure to search is the leading cause of male impotence on XDA
If you don't know how to recover if things go wrong, what are you doing flashing custom roms ?