lol, I was doing exactly the same, mostly because the gnome app for it (webapp-manager) does not do one thing I badly want : open all non-app links in the default browser and not on instances of itself. Also, I love the webkitgtk project and this allows me to give it an usage.
I will give a look at your project, I think is better contribute to it than have two (or more) projects doing the same 😜