Ergon-1UI7 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