WordPress.org

I activated the plugin and nothing happened

This plugin will only redirect users who are viewing the site on a mobile device. You also must first update the redirect URL within the plugin settings.

How can I give my users the option to view the full site

If you want to use this feature set a link to "example.com/?view_full_site=true" anywhere on your mobile site. The cookie will expire after one day. You may change the expiration time by changing the time()+86400 on line 43.