Limits App ( http://limitsapp.com ) - An iOS app to track what drinks you have and discover when you're over/under the current drink driving limit. Just a fun app so we can exercise some freedom on all those little big details that clients seem uninterested in.
We've got a good disclaimer for the few that decide to go down that route. As an aside, I've seen the police use this formula for "back counting" alcohol consumption.
