It is a new service for the Files app that allows Chromebook and Chromebox users to connect directly to SMB (Windows) server shares. I immediately installed it and connected to my NAS4Free server with no problems.
The NAS4Free share appears in the left pane of the Files app, and everything is immediately available.
I was ecstatic, for the one downside of Chromebooks and Chromeboxes is that the only way to connect to a local resource is to use FTP by typing and FTP address into the browser.
For example to play a video from my NAS server required me to connect with ftp://192.168.1.250/ and then right-click a file and save it locally to play the content. SOME FTP content will play directly in the browser, but most has to be saved locally.
Compared to the point and click possible between Windows and Linux machines and network shares, ChromeOS has been pretty clunky.
Unfortunately, I was unable to connect to my ASUS router. It has a 3TB USB drive connected and shared as SMB and FTP. All attempts to date have failed to connect. This is unfortunate, but for an App that has only been available for days, it is a VERY GOOD start. SMB is a difficult protocol to cope with. Microsoft spent years trying to break connections from any device that was NOT Windows until they finally realised it was in their best interests to let everybody connect to their servers.
UPDATE: The latest version of this app now connects to everything in my office perfectly. I have connected to a NAS4Free box, ASUS router and a Seagate Wireless Plus Mobile Storage / Wi-Fi hub that is my travel server.
The Service/App is not perfect. Pausing a video during playback causes a timeout error, and I wonder if the failure to connect to some of these SMB devices is simply the slow speed of low powered devices such as router based SMB shares and NAS boxes that take time to spin up sleeping hard drives.
I am confident that Yoichiro will continue to work on this, as long as he gets some encouragement, and with time it will sort out the problems.
As I worked away with this I noticed something new in the usually simple Files left pane. A new item at the bottom. Add New Devices!
Added to this the exciting Dropbox implementation done as the first proof of concept for the new API Google released, and some seriously exciting things are happening in the Chromebook / ChromeOS world!
I do NOT want ChromeOS to grow into the bloated sloth that is Windows, but by adding features such as connecting to local network devices, the ability to connect to Bluetooth headphones and speakers and access phones via Micro-USB / OTG in just the last month or so.
ChromeOS is getting very interesting.