This is not an application, you need install a home launcher to activate this theme ,
Our Apps support all major launcher listed below
Smart Launcher 2
Mini launcher and more ...
Also include Hq wallpapers and icons
Very Easy to use
To Apply the theme
Go to Launcher Settings -> Themes -> Select One plus theme -> Apply
To Change icons in tsf shell ,
Long tap on icons in home screen and browse your icons from One plus Themes
If u have any trouble During install contact us via email, we are very happy to take care.
thank you for your understanding