My family and I play Bingo on a regular basis, and we use a small ball machine that determines our numbers, and if we were to lose any of them, the entire set would no longer be useful. This app is perfect for avid bingo players who don't want to mess around with a machine. However, I do have two complaints. The main one is that it only calls out numbers, and it would be helpful if it showed the corresponding letter as well. For example, B-13 as opposed to just the number 13. Secondly, if the app would save your settings so that the next time you use it, you don't have to set the number of balls, and time between the balls again.