Adeptus is an issue tracking application I've been using for personal projects such as reZonator or Procyon or Adeptus itself.
Adeptus manages project issues storing them in a single SQLite database. It doesn't use its own server, and you are free to choose favored sync service, like Dropbox or Google Drive, to share the database between your working machines.
Sorry for that, I'm tracking my issues in Russian, but you can get a clue anyway :)
Clone the repository
git clone https://github.com/orion-project/adeptus
Update submodules:
cd adeptus
git submodule init
git submodule update
Note, that submodules are in 'detached head' state by default.