Ask HN: Volunteering for a good cause; which nonprofit should I shoot for?

Hey HN, I'm taking a class that mandates each student to have one, unpaid, contract position with a registered nonprofit. Since none of the companies near my university are tech-oriented, I've been looking for alternatives online that would make the most out of my skill-set. Of the nonprofits out there, do you know what one could definitely use a free full stack application developer? Thanks in advance!