Let me introduce my friend Endy Muhardin, Endy, he is very knowledgeable with software development and distributed revision control system such as git in particular.
He and I will assist contributors to code for playSMS.
When you have questions around playSMS, especially about howto code and contribute back to playSMS, please ask in the mailing list and he (or I) will answer your questions (on his or my spare time, as always, like any other free software community).
Contribution workflow is as follow :
1. Fork playSMS github repo
1.1. Login to Github (http://www.github.com)
1.2. Open playSMS github page (https://github.com/antonraharja/playSMS)
1.3. Click Fork Button
1.4. You will have your own repository, e.g: https://github.com/endymuhardin/playSMS
1.5. Clone your github repo to your local computer/laptop (RTFM git please, RTFM: Read The Fine Manual)
2. Create branch to hold your modification. You should create branch for specific task e.g : add feature, bugfix. This is called topic branch (RTFM howto create a branch in git)
3. Commit your modification to your topic branch (RTFM git please)
4. Whenever you feel your branch has matured (well-tested, properly formatted, worked), create pull request (http://help.github.com/send-pull-requests/)
5. I will review your pull request and do either one of the following
5.1. Accept your pull request and merge your branch into my playSMS repo, or
5.2. Ask you to revise/fix your code
6. If your branch has been merged into my playSMS repo, it will appear in next release (with your name on it, also on README)
7. Should you have any questions, asking for statuses, or anything related to this topic, please post your questions in mailing list