I don't know how young is young, but finding this PBS app was great: https://pbskids.org/apps/pbs-kids-games.html https://pbskids.org/apps/pbs-kids-games.html

I don't know how young is young, but finding this PBS app was great: https://pbskids.org/apps/pbs-kids-games.html https://pbskids.org/apps/pbs-kids-games.html No ads, works disconnected from the internet, and games are pretty simple and not driven towards some kind of monetary business system.