"nut tool" aka a wrench/spanner? lol
I have the Origin8 pb&j tool.. it's got a lockring wrench, nut wrench, supposedly you can use one side as a tire lever, and it has a bottle opener and can attach to water bottle bosses. attaching to the bosses sounds cool except as robertfrapples mentioned, you either have to give up a cage or temporarily remove a cage just to use the tool
bottle openers on bike tools seems a bit irresponsible imo