Thanks so much for the link, for some reason I couldn't find this link. I don't write write access on Medium; was wondering how their editor worked.

I am working on an open-source app inspired by medium. Hopefully this should be done in a week's time. Here is work in progress: http://i.imgur.com/ZYWRc8k.png

I'll also borrow your/medium's idea of showing the toolbar when text is selected.