Repository for mobile apps to interface with Kaviar - http://db.systemsbiology.net/kaviar/
This link goes through how to pull directly into XCode but you want to first set up the remote git repo. Go to Source Control in the toolbar and hover over the project. Go to "Configure" and select remotes and hit the "+" in the bottom corner. Add the address and name.
To pull, you first have to commit all changes to the local repository. Then go to Source Control and hit "Pull" to make a pull. Then you will have to resolve any issues. A "C" next to a file in the xcode project indicates that there is a conflict that should be resolved.