I started working on HG two years ago, open sourced the code [2], but never really had the time to give it the love it needs (updating to a newer version of React, make the code nicer, blog about it...).
If you'd like to give it a boost, I'm happy to leave it as a playground and support where needed -- assuming the core functionality will still be there. We've had already a good number of friends from all over the world contributing with UI improvements and translations.
Incidentally this is how I learned React, and in fact this is not much more than React tutorial (searchable list) with a slightly better UI, and backed by a google spreadsheet. I also integrated ads sense, with the idea to pay back the $12/y of the domain, but I think there's some issue loading. Overall I think a project like this could teach you quite a good number of reusable skills.