The question is, how elaborate you want it to be. And how far the distance is, between your teammates.
If you are able to meet and you "just" need a way, to track status-updates, perhaps updating the readme on git would be enough (if everyone read it).
Or you could use a small and nice project-management-tool like Splendid Bacon (https://splendidbacon.com/)
You could use Skype (or anything like that) to discuss things (if you are far away from each other), if you can't meet in person.
Or - if you all have an email-adress with the same domain-name - you could use yammer to chat/discuss, make planing documents, and so forth... (http://yammer.com/)
We've been using 37 Signals https://launchpad.37signals.com/signin, which has worked great and we send emails constantly (saving docs/files with a date for easy reference)
If you are able to meet and you "just" need a way, to track status-updates, perhaps updating the readme on git would be enough (if everyone read it).
Or you could use a small and nice project-management-tool like Splendid Bacon (https://splendidbacon.com/)
You could use Skype (or anything like that) to discuss things (if you are far away from each other), if you can't meet in person.
Or - if you all have an email-adress with the same domain-name - you could use yammer to chat/discuss, make planing documents, and so forth... (http://yammer.com/)