I saw that Osu!Stream was mentioned, but it got a little bit of flak. Any reason why? The game is a REALLY awesome clone of EBA. Between that, Cytus, and Jubeat (Jukebeat), the iOS is starting to really put together a nice range of Bemani titles available.
Asides from the super poor track selection, it just felt off to me. The rhythm of the "taps" didn't connect with the music as it does with EBA and Ouendan. At least that's what I got from it.