The WiFi Assistant feature from Google's Project Fi wireless network turned out to be one of Nicole's favorite parts of the service, and now more people will have access to it. Google announced today that it's bringing the ability to "automatically and securely connect" to over a million hotspots to Nexus owners in the US, Canada, Mexico and Nordic countries. WiFi Assistant identifies open, unprotected hotspots with good connections, and if you don't want your network on the list then you may want to take a look at these instructions (or, just make sure it has any password protection at all).
Since it's operating on open wireless networks by nature, WiFi Assistant uses a Google VPN to try and secure the connection. Ideally, it just makes sure you have an internet connection that you can trust, wherever you are, without the need to do anything manually. The FAQ should do a lot to explain exactly how the feature works and give you some time to get used to it as the feature rolls out "over the next few weeks."