This repository holds the specification of PGPAuth. You can use it to develop custom apps and servers compatible with all the other PGPAuth- compatible programs.
Please try to integrate your new features in existing apps first, to prevent having the user choose between features only in app A and those in app B.
If you create an app for a new platform, you can get a repository in the PGPAuth organization here on GitHub, giving your app an "official" state.
Feel free to fork, enhance and do a pull request :) I will review and maybe add them :)