If you're running a stock, rooted Galaxy Note II or Galaxy S 4 and want easy access to some things that normally require manually editing system files, we've got the app for you. It's called Note 2 Hidden Settings, and does exactly what you'd expect: offers access to otherwise hidden system settings.
Aside from requiring root access, the app is simple enough to use – just install it and run with it. You'll find simple toggles for things like shutter sounds, scheduled messaging, rotation control in the gallery, and many more. Naturally, this app is only applicable on stock systems, as these options are specific to TouchWiz and aren't present on most custom AOSP-based ROMs.
If you meet the qualifications, there's no reason not to have this app installed. It's a freebie in the Play Store – head below to grab it.