24 game solving app

I haven't updated this blog in a while, so here's one of the things I've been up to.  If you are not familiar with the 24 game, or challenge 24, it is a game where given 4 numbers, you have to make 24 by adding, subtracting, multiplying, and dividing the 4 given numbers.  For example, for the number 5,6,7,4, the solution is (7-5+6) *4=24.  I love this game, and it is one of very few things I am great at.  Sometimes there is a set of numbers I can't solve and it is very frustrating, so I made a java program to find a solution.  Then I turned it into and app and uploaded it to the Google Play Store.  It is available here.  Also, the source code is on github.