Team-GPT

I've bought the 2 tier version with up to 25 members. I've used this in a classroom environment and it worked great.
One point for improvement, it is now setup that you need to register members with valid e-mail addresses. Which is difficult to maintain since in a classroom situation members will vary each time, having the option to also be able to use username/passwords instead would be much easier. Also be able to change passwords for all members to a single new password would make life much easier.