Test Your Website With Chrome. (Iphone, Android, Pretty much on all devices)

Sorry but all this does is change the user agent string, it doesn't change the rendering engine, viewport size, emulate touch events or anything else you need to do proper tests.

This is a gross overstatement, the setting simply changes your user-agent string. Which, honestly, serves very little purpose. Most cases for user-agent sniffing that come to mind are related to something about that browser's rendering engine (i'm looking at you IE!)

Now, if chrome could render using the Trident engine from IE7, I'd be impressed.

Please don't just switch your user agent and think that your website looks fine in IE 7.... go get IETester (http://www.my-debugbar.com/wiki/IETester/HomePage) or something similar.