- The most popular is probably Italki. It is quite hard to be accepted onto the platform as a new teacher, but I've met some teachers who make a decent income here. It mostly depends on how much competition you have for your language. Majority of students know about this platform.
- The cheapest is maybe Preply? They are pretty good for students, not that good towards teachers. They take a 33% cut at the beginning and it sometimes feels like a race to the bottom in terms of prices. That's a plus for students then, but the subscription approach feels a bit unfair I've heard.
- Verbling is pretty famous too. Kids are legally not allowed to be taught here, and they've introduced criminal background test requirements for teachers.
Do you know of any other platform?
My secret goal this year is to develop something similar, but Bitcoin-centric (where teachers and students can get paid over LN), but as this was already a goal a few months back, I don't want to commit to anything at this point.