The app is very, very well done. The touch controls are a great metaphor for filling the cups, and there's just the right amount of repetition and practice to actually teach you the finer points of pouring drinks and tending bar (the game's script was co-written by an actual cocktail journalist). And completely outside of the core gameplay, the story and characters are hilarious, and the art and music create the perfect mood of being behind a counter and dealing with waitresses and regulars.
Nimble Strong is quite a gem, and if you're leery about jumping in on the full US $4.99 version, there's a free version to try as well. Playing the free version for just a few minutes will probably sell you on the real thing, though. With drink recipes available as you unlock them, it's like taking a bartending class, without the spilt booze all over the place.