reNIX is a beautiful Android like theme for Gnome Shell. If you installed reNIX GTK3 theme, this will nicely complement it to make your desktop look good.
Make sure you have user-theme-extension installed. Load the GNOME Tweak Tool (available in Ubuntu Software Center) and go to "Theme" section. Click the Shell Theme box and locate the zip file downloaded from link above. Select the theme in the drop down box.