Learn Earth
Cheap and structured in a way most chatbot tutors are not: you get an ordered path and graded practice rather than an open conversation you have to steer. Six dollars a month is easy to justify. The unknowns are who runs it and what verified knowledge actually means in practice, since neither the operator nor the sourcing is disclosed.
Pros
- Any topic is broken into ordered steps rather than answered in one block
- Practice sessions grade themselves and explain the miss immediately
- Premium is 6 USD a month, well under most tutoring subscriptions
- A permanent free tier exists, limited by a daily meter rather than a trial clock
Cons
- No company name, country or founding year is published anywhere
- The verified knowledge claim is asserted with no visible sourcing or citations
- The daily energy meter gates the free tier hard enough to interrupt a study session
- Browser only, with no mobile app, offline mode or API