Teachoo (https://teachoo.ai/) accompanies the understanding of given topics by asking questions or writing an explanation.

Guided mode asks questions to help with step-by-step understanding with clues in case of blockage.

Images and graphs proposed in the answers.
Creation of flashcards (without AI) possible.

The “Explain via a video” option gives the complete solution without questioning. The videos did not work during the tests.

Works with 4 Gemini models.

Designed by the creators of the IaskAI response engine.

Free and without an account, seems unlimited.