Athenion

Athenion is a web app for adults who want to understand a topic, not just get an answer.

You tell it what you want to learn. It turns that goal into a plan of concepts and teaches them one at a time, by conversation. After each idea it asks you to explain it back in your own words and checks that explanation, so you find out what you actually understood. Then it schedules a review of each idea right before you would forget it.

On the Plus and Pro plans, programming topics add hands-on practice in a real workspace.

Works in English and Spanish. Built and run by one person.

Paid, with the first month free on every plan. Then Basic $5, Plus $10 or Pro $30 a month.