Creative Commons Non Commercial 3.0 License
Icon images from iconmonstr.com see website for license terms
Some additional icons from metroicon.net courtesy of Piers

Installing the latest version
1) In this page click on the green button Clone or Download --> Download ZIP
2) Uncompress this ZIP file. This will create a folder named skin.arctic.zephyr.plus-master
3) Rename that folder to skin.arctic.zephyr.plus
4) Compress that folder again into a ZIP file. 
5) In Kodi, use that ZIP file (and not the original one) to install the plugin in Settings --> Addons --> Install from ZIP file.
6) You are done!