Gaskit a git-backed issue tracker. It uses a branch in your local git database to store the tickets.
Gaskit was created as a proof of concept for using Git as a database for an application. It currently only runs against itself.
There is a lot more work to do before it is really useful. If you'd like to help out, clone the repo and run the app to see what needs done.
$ bundle install
$ bundle exec rackup