The Chrome Web Store originally launched in 2010, and serves as a hub for installing apps, extensions, and themes packaged for Chrome. Over a year ago, Google announced that it would phase out Chrome apps on Windows, Mac, and Linux in 2018. Today, the company sent out an email to developers with additional information, as well as news about future Progressive Web App support.
The existing schedule is mostly still in place - Chrome apps on the Web Store will no longer be discoverable for Mac, Windows, and Linux users. In fact, if you visit the store right now on anything but a Chromebook, the Apps page is gone. Google originally planned to remove app support on all platforms (except Chrome OS) entirely by Q1 2018, but Google has decided to transition to Progressive Web Apps:
The Chrome team is now working to enable Progressive Web Apps (PWAs) to be installed on the desktop. Once this functionality ships (roughly targeting mid-2018), users will be able to install web apps to the desktop and launch them via icons and shortcuts; similar to the way that Chrome Apps can be installed today.
In order to enable a more seamless transition from Chrome Apps to the web, Chrome will not fully remove support for Chrome Apps on Windows, Mac or Linux until after Desktop PWA installability becomes available in 2018. Timelines are still rough, but this will be a number of months later than the originally planned deprecation timeline of "early 2018".
We also recognize that Desktop PWAs will not replace all Chrome App capabilities. We have been investigating ways to simplify the transition for developers that depend on exclusive Chrome App APIs, and will continue to focus on this - in particular the Sockets, HID and Serial APIs.
Progressive Web Apps and Chrome apps are both designed to make web apps fit in more with native desktop applications, but the similarities end there. PWAs are cross-platform and cross-browser, while Chrome apps are obviously limited to Google's browser and use proprietary Chrome APIs.
Chrome on Android already supports installing PWAs, even giving them their own icon in the app drawer. It will be interesting how Google gives that same treatment to Windows, Mac, and Linux.