Robinhood is the ultimate 'look over their shoulder' app. It's the most intuitive way to teach a teenager about the stock market, but it’s also built to be addictive. If you let a teen use it, you have to be the guardrail against the app's darker impulses—specifically its push toward crypto and prediction-market gambling.

It’s a great tool for a 15-year-old to buy $5 of Disney stock and watch it for a year. It’s a terrible tool for that same 15-year-old to 'day trade' on the bus. Intentionality here means treating it as a classroom, not a hobby.