Dark Aura GTK 3+ Theme

This is one of my favorite GTK themes and i've been using it and testing it on Ubuntu Gnome 15.10. Now, it's updated to Gnome 3.18. This theme is also compatible with most gtk 3 Desktops. To apply this theme, you can use gnome-tweak-tool, Unity Tweaks Tool, or Ubuntu-Tweak.

To install this theme, download package from here.
Extract downloaded file to .theme folder on your home directory. If you can't find it, on /home hit Ctrl + H then create new folder name it  ".theme".
Alternatively, but not recommended, Copy Extracted file to /usr/share/themes under root privilege.
Lastly, apply theme using tweak tool.