Stampede Design
You’re probably already familiar with responsinator, a tool to check a webpage in a variety of viewports. Google is now offering an alternative by the name of Resizer which is made to test Google’s very own Material Design across many different platforms. A number of breakpoints can be tested.
Desktop: 480px, 600px, 840px, 960px, 1280px, 1440px, or 1600px
Mobile: 360px, 600px, 720px, or 1024px wide