Bikerz is an icon pack. It is not a stand alone application you need a third party launcher to apply it.

***Note***
Please check the following videos on how to setup your phone with Nova and Niagara launchers:

Nova Launcher:
https://www.youtube.com/watch?v=B0npv8Z5sW0

Niagara Launcher:
https://www.youtube.com/watch?v=f3dvqiXTwC4&list=PLOvXK6kvTwvlCViyD1_BK3URZbPafQ5nN&index=4

What's included:

★ 1.400+ HD icons (256x256)
★ 180 matching HD cloud wallpapers!
★ Launchers support: Action Adw AdwEX Apex Atom Aviate GO NextNova Smart Solo...
★ Icon masking for un-themed icons
★ Dynamic calendar (For Nova Launcher)
★ Alternative icons to choose
★ Updates.