See an example here: http://projekte.acsany.de/windowsize-note/example.html
What is it?
A tool to help finding breakpoints while creating responsive websites. It shows the current size of the browser window in px and em.
How does it work?
Just add WindowSize-Note.js to your site while you are working on it. A little red box will be appended to the body-tag of the website.
What does it need?