neotree can work with vc-mode. So it works like Atom.io. However its feature is disabled as default. Please add following configuration to your init.el for enabling it. You also enable vc-mode.
(custom-set-variables '(neo-vc-integration '(face)))
Screenshot is here. Modified files are highlighted in magenta.
neotree supports showing vc information by face and char. We can also enable both of them as below.
(custom-set-variables '(neo-vc-integration '(face char)))
This version screenshot is here. There are
E(means edited) characters at Modified files.
Face names of neotree vc information are
neo-vc-edited-face). And characters of it is
neo-vc-state-char-alist. You can custom as you like. Please read documentation or source code in more detail.
enjoy hacking neotree.