I really didn't know that. However, I can recommend some useful educational mobile games to you. Is to design knowledge points into game levels. Children can learn while playing games, and self-study becomes interesting in interaction. This game is called fun class.

Senior one has comparison, building a house, comparing distance, counting, 1-5 subtraction, water drop addition, understanding plane figure, digital connection, understanding three-dimensional figure, crazy addition, time highway and subtraction elimination. Games such as "1 1 to 20 understanding", "farm addition and subtraction", "position understanding", "RMB understanding", "number understanding" and "law-finding adventure".

In the second grade, there are "addition within 100", subtraction within 100, length unit, angle understanding, multiplication table of 99, observation object, preliminary understanding of multiplication, digital breakthrough, division within the table, line segment understanding, graphic movement, division with remainder, graphic symmetry, digital filling in the blanks, mixed operation and turning numbers into fun.

I hope it helps you.