One in particular would Ameba TV. They have it on the Roku box.
Ameba gives you total control over what your children watch by allowing you to preselect from thousands of educational and music themed shows; programs that are designed to spark your children’s curiosity, take them back in time, empower them to explore, learn different languages and develop skills that will prepare them for school and for life. New shows and music programs are continually uploaded from the best content creators in the world. There is always something to see on Ameba.