This tool has been built to help with testing your responsive websites while you design and build them.
You can enter your website's URL into the address bar at the top of this page (not your browser's address bar) to test a specific page.
Unfortunately, with the way browser security works, you are unable to navigate your site through the frames that your website appears in.
The only way this is possible is if you host the testing tool on your website's own hosting.
I have provided a github repository for you to download and install the tool on your own site.