There's a _huge_ cottage industry of edu apps and programs that are both hugely expensive and not better at teaching, consuming a lot VC and end user $$$. As a first step, this seems not bad at all.

I do agree that it would be better to dial in on a pupil's interest than the grade level (my kid may be 7th grade in English but 9th grade in Chemistry, for instance.)

[Edit: fix typo]