The invite button activates as you type, a comma or a space separates addresses, and an address you have already invited is quietly skipped.

A shared link never expires but dies the moment you generate a new one; an emailed invitation lasts seven days. What a student sees on a dead one.

Signing up as a teacher creates a student account beside it: one login, two separate libraries, and a switch that ends your other sessions.

Work done through a task link is recorded nowhere: the person sees their own result and the teacher sees nothing. Assign the task when you need the result.

Student and teacher are two account types with different screens, and one person can hold both and switch between them.

Invitations add up rather than replace one another, and only the teacher can undo the link.

Progress is saved on the server as you go, but answers are final and a finished task cannot be retaken.