Most apps "solve" the tracking problem with quizzes. But recognizing a word in a list is easy — using it in a sentence is where real understanding shows up. My kids could ace a quiz and still have no idea how to actually use the word.
The other missing piece is the memory curve. Without spaced repetition, words just evaporate — they'd "learn" something on Monday and it'd be gone by Friday. The research is clear: revisiting at increasing intervals is far more effective than cramming. Most kids' apps ignore this entirely.
I built Wordie for my own kids, but realized the same pain points probably resonate with other parents. Kids read short AI-generated articles with vocabulary words at their level, then write their own sentences for each word. I (the parent) review them before the word moves forward. Words that pass enter a spaced repetition queue. Ones they struggle with stay in rotation.
Built with a lot of AI help — which felt fitting for an AI-powered kids' app.
Would love feedback from other parents.