Very good assist for phone design
This app is simple and does the job of showing the browser experience as it would be on an iPhone. Some people say to use Chrome and switch to the responsive view. This is even simpler. My regular browser shows me the page in desktop view, and this app shows me the phone view. You can even input any URL from a server and the app will display in the phone view. Does not have a lot of fancy controls, but it works.