I want to recommend a game I created to learn letters, numbers and colors.
It's a free Android game and you can download it from Google Play (See link
The game is for preschool children. Game is based on matching pairs, audio identification and fun memory game
Kids play with it for an hour and doesn't get bored
They like the gifts and everyone knows when they received a trophy
It helps them a lot in recognizing numbers and letters
See game in Google play (Click on link
It's free game and you can see the introduction clip