There are so many incredible piano teachers on the web who generously share the awesome games they have made. Many of those teachers also have blogs about teaching piano. There is a lot of wisdom and experience in those blogs. They give great ideas and tips.
I am going to share some of the websites I look at for games and, when I have time, to read blogs. Some of them even have free piano music! Some of the websites offer free games and music, and offer an option to buy piano music and games geared to teaching piano.