We'd love to accept your patches and contributions to this project. Just remember this project is designed as a playground for people to develop their skills. As such your proposed changes should keep in mind this project's intended purpose as platform for skill development. If you simply want to develop cool features based on this project, that's great - just fork this project and go wild.
Contributions to this project must be accompanied by a Contributor License Agreement. You (or your employer) retain the copyright to your contribution, this simply gives us permission to use and redistribute your contributions as part of the project. Head over to https://cla.developers.google.com/ to see your current agreements on file or to sign a new one.
You generally only need to submit a CLA once, so if you've already submitted one (even if it was for a different project), you probably don't need to do it again.
All submissions, including submissions by project members, require review. We use GitHub pull requests for this purpose. Consult GitHub Help for more information on using pull requests.