This math app is very similar to the 24 game where the player(s) try to write an equation using four numbers to equal a target number. The target number can be predetermined by a setting and the choices are 12, 24, or 36. The students who I've had use the app enjoy it and find it a good challenge. I've had kids work on a problem using white boards and then when a student thinks he/she has an equation that works, we check it and then put it into the iPad. The app reviews basic arithmetic skills and could be used for order of operations practice. I've had individual students use it as well as a group activity.
There are times when the app tends to freeze and I've had to quit the program and reopen it to be able to keep working with it. This is the only major "glitch" I've had with the app so far.