I received a free code for the app Moose Math. It's geared for K-1st graders and has activities tied to the Common Core math standards. There are 3 places for students to visit in the town--a juice store, a pet store and lost and found. Math skills include counting, addition, subtraction, shapes and colors. As students progress the levels get increasingly difficult. The initial levels were definitely easy for my 1st graders, but they quickly moved up to math that made them think. Their favorite seemed to be sorting/identifying shapes and colors in the lost and found.
I appreciated the ability to check-in my student's individual progress. Also, the nutritious nature of the juice shop ties in well with the nutrition/food groups unit we are just starting.