There is a new browser on the block and its name is Blisk!
The Blisk browser was created specifically for developers and can be configured to emulate multiple devices, auto-refresh page rendering as files are edited, and synchronize scrolling between desktop rendering and device emulation. Future featured include screenshots, video captures, analytics, and more. Blisk is available as a free download for Windows at https://blisk.io. Mac and Linux versions are in the works.