> Apps to fight apps has never worked for me. When I'm bored/tired enough, it becomes a game to disable my own restrictions.
OneSec [1] is the only one that worked for me. It's quick enough that I'm not tempted to disable it, yet annoying enough that makes me think twice if I really want to open app X for the third time today.
Also it's just a polite nudge, rather than a full block, or condescending messages saying "you've hit your time limit for today" (that make you feel bad and make you want to immediately disable the thing in the first place).
Wish parental controls were designed with the same principles.