It's a tough call for a relatively short term project... I think you will have to go down the 'do something IRL and post for rewards' route - anything more technical would probably be beyond new users with no technical knowledge.
But there's plenty of ideas in the comments.
I'm interested, are you giving them the option to use other Blockchains too....?
Yes, my hope is that [1] each student will learn something meaningful just through the process of trying to create something of value for others and [2] some students will choose to continue developing or maintaining whatever they start for the class.
Not this semester. It is an experimental course, so I am trying to keep things as simple and straightforward as possible.
Oh it's a whole course?
Very interesting!
It's a 1-credit-hour course. We might expand it to a 3-credit-hour course next year.