Is there a module (or another way) that allows students to upload files to a folder that other students can see and possibly change what another student has uploaded?
Fredrik, greetings! There isn't functionality like this in Canvas. My recommendation is to try something like Google Drive, Dropbox, or possibly Office 365. Google and Office 365 can both be integrated into Canvas and I've used the Google integration (called "Collaborate") in my class and it worked pretty well.
Hope this helps! Kona
Retrieving data ...