The add-on provides a simple way to change the view to mobile with a single click and adds a toolbar button that is used to toggle the view. In this way, you can easily switch between the mobile and desktop views of a website. 

To make this addon work, you need to add a user-agent string for each mobile platform. For Windows, you can copy the string to the designated area and then restart the app.

Now, you can simply click on the toolbar button to change the view of the website. You can also enable or disable the addon to save some battery life.

When the addon is enabled, it adds a new option on the options page of the website. This new button allows you to change the view. When it is disabled, the website loads as usual.