if you compare with Giteye (the Free fit client from collebnet), apparently following feature is more convenience than SourceTree:

• Any platform Windows, Mac, Linux
• All self-included (zip), no need install git/ssh, no need for local admin for windows installation
• Embedded file explorer, you can browse structured folder from the client
• Import all your existing git repo in one step
• Interactive git rebase GUI view
• JIRA integration as Task management to allow you have a local task scheduler