Recently I came across this pretty neat math resource called Knowledgehook. The best way I can describe it is, is if Kahoot and Freckle Math (previously known as Front Row) had a software baby, this would be it. Knowledgehook allows teachers to push 'Missions' to students that they must complete. The questions look very similar to state standardized tests and provides them in a non-overwhelming amount. It also features a 'Gameshow' ability. Gameshow is a Kahoot styled activity that can be not only done in a competitive mode, but also in a collaborative mode. The collaborative mode promotes students taking their time to solving the problem and also gives them the ability to submit proof of how they solved the problem.
Knowledgehook provides content for grades 3-12, but younger or more advanced classes could take advantage of the 'Custom Content' feature to make it fit their needs. If you want to see Knowledgehook in action, please watch the tutorial below to see a overview of it's features.
This blog contains resources available through the web and accessible through a variety of programs.