You're leaning correctly...
Chess app for beginner kids.

Resources to help you help your children...
Chess Courses - Instructional Resources...
https://www.chess.com/blog/RussBell/beginners-chess-course-instructional-resources
https://www.chess.com/blog/RussBell
Ages 5 and 6. Any suggestions? I'm leaning towards Chesskid.com, but wonder if anyone has recommendations.