Oh Beautiful Brains has been making some solid puzzle games with Tentis Puzzle [Free] and Tentis Minute [Free], which combine number-adding mechanics with puzzle games. Tentis Drop is the next game up, and it uses some of the familiar Tentis mechanics, but in the context of a puzzler where pieces are dropping. Number tiles slowly descend from the ceiling and can be moved, but you can also ombine different tiles in order to add up their values, all the way to 10. Get three tiles adjacent to one another, and they disappear. Check out some gameplay with developer commentary:

Oh Beautiful Brains needs beta testers for Tentis Drop, and feedback is especially requested as to gameplay and pricing for the game. If you wish to take part, you can sign up on the form here. Tell 'em TouchArcade sent you. Seriously, I recommend doing that on the form because it might help get you access sooner...