What was the height of the iPhone again - minus the Safari UI? How much space is there above the fold on a HTC one?
Ever got frustrated with resizing your browser window just to see your page break again in a new dimension you haven't anticipated?
I wrote Chameleon to help develop responsive websites. It's a Chrome plugin to preview your site simultaneously in popular device view-ports. Or add your own view-port sizes in the options. Chameleon will live refresh all views when you update the original site, or navigate around it too.
Check it out, let me know what you think!
Chameleon