If you have a large group of students, or you are teaching remotely, you may want to continually check on individual or group progress with a particular task or program.
You can do this with classroom.microbit.org
Another approach to this would be to use a shared document (eg Dropbox Paper or Google Docs) and ask the students to paste the URL to their code beneath their name/ID, which they can update at set intervals.
To generate the URL, select the share button 
at the top left of the editor window, select publish and copy the URL that is produced.
They can then paste this link into the shared document.
The project will open from the point that the link was generated, so if a student updates their project they can share and paste a new link.