My kids are beyond the basic learning content. I would love to see some fun learning content as well as overall learning content. My kids love Owie Tv songs from YouTube and stuff from scratch garden (youtube). How about content fun and play/songs with synonyms, antonyms, syllables, idioms, and other yms of English.
Another series on fun/songs with parts of speech. Each card is another part of speech. Series 1 could be basics (nouns, verbs, and so on). Then a second series of cards on the more complicated parts of speech.
I would love to see progressive math series cards. Fraction fun for instance. Fractions, Decimals, percentages, division connection through music. Fun with negative numbers. Silly math cards.
Also, I 100th the ideas I assume are already posted about more brainbot and Ladybird adventure cards. My kids absolutely love these.
There is a large homeschool base and a large neurodiverse base.