I question the morality of any adult that purposely creates content aimed at children that have nothing to do with the best interest of the child and everything to do with the best interest of the adult. When I was growing up we called that strategy “GROOMING”! 

Created for lower elementary students (6 to 9 years old)

https://www.titlewave.com/search

Child Development at those ages:

https://raisingchildren.net.au/school-age/development/development-tracker/6-8-years