One of the hot topics at Google I/O 2018 has been the evolution of Material Design. The website has been overhauled and lots of new guidelines have been added, with some of the changes being discussed in sessions at the conference. Material Theming is also being introduced to help developers implement the design language in their apps while retaining their own style. Another tool, Material Gallery, has just been launched to help designers organize their projects.
Available on Android, iOS, and the web, Material Gallery is a place for design projects to be uploaded for teams work on them together. You can invite any number of people to review or collaborate on your designs, which could be in the form of screenshots, sketches, or whiteboarding sessions.
The app allows you to inspect elements and generate redlines, as well as offering lots of other helpful information. Feedback can be left by project members and so revisions can then be easily tracked. It's possible to attach external links such as documentation (on the web app only, it seems), with colors automatically assigned to different Google Drive document types.
With the Material plugin installed as well, other developer resources such as the Material Theme Editor and the component library can be linked, plus your Sketch artboards can be synced. Sign up with your Google account and you'll find a sample project already there to show you what's possible and help you get started. There's more information on the Material site.
To give it a try, install the Android app via the Play Store link below, or sideload it from APK Mirror.