I noticed that the description says, "Inspired by SourceTree" for the line-by-line staging feature, but actually git-cola[1] invented that feature, before even git-gui, and SourceTree just copied us 8^)
Also, if you're going to have that feature you should consider implementing the entire thing ~ it's not enough to have line-by-line (un)staging. You also need line-by-line reverting of modified changes, and support line-by-line (un)staging while amending commits.
I'll definitely be sharing this with my sublime-using coworkers, very cool.