This is a Chrome extension that will resize your browser window to the break points in the code of the current site you are viewing. Those sites without breakpoints show a blank window in the extension.
Responsive Inspector is helpful to see all of the breakpoints a particular site uses. Some have several breakpoints, other sites have just a few. It's a good learning tool.
It's a wee bit buggy sometimes, but it's being updated regularly.
If this link does not work, just search for "Responsive Inspector" in the Chrome browser Extensions.
Adobe's Project Mighty and Project Napoleon are cloud enabled hardware. They enable a designer to carry his style anywhere he can access Adobe's cloud.
Mighty is the stylus. Napoleon is the "shape tool".
The stylus, among other things, can create a Kuler color profile from your iPhone, then paste that profile onto your iPad. You can cut & paste across multiple devices.
The future of design is giving designers the ability to create at the same professional quality while on the road as they do when there at their desks.