This one was super interesting.
Have been looking at Monero based voting systems for a while as I think it's a distinctly lacking application of cryptographic technologies.
do check out the website : cryptopoll.org
[It's not "Monero based" but it copy and pastes the ring signature part of the code as the basis for a voting mechanism - each participant's PGP signature joins a total ring and creates a validating but obfuscating voting mechanism]