Back when Google officially announced Project Fi, many were enthusiastic and excited about the possibilities for having a wireless service that fits best with their needs. That some excitement was short lived for some when they found out that Project Fi was only officially supported with one device: The Nexus 6. While this is no device to scoff at as it provides great specs and an awesome user experience, it wasn't very inexpensive at the time and many people who likely would have considered testing out Project Fi already had a phone. Google still hasn't sent any word that Project Fi will support more phones any time soon.
To that end, it's true that Google hasn't announced any support for the service with other smartphones just yet, officially or unofficially, but when it comes to unofficially, it appears that the new Moto X Pure Edition model may just "unofficially" support Project Fi. Unofficially is the key word here as it seems ZDNet's Kevin Tofel was able to get Project Fi running on his Moto X Pure Edition that came in for review after throwing in his Project Fi SIM card, but there were some things that aren't necessarily working as they would on the Nexus 6. For example, connecting to Sprint's network couldn't be done manually and when connected to T-Mobile's network the phone would only connect to T-Mobile's HSPA+ speeds and not LTE, although it's noted this never caused an issue. That couldn't be said for everyone else though who might attempt to try this.
The good news is that call handoffs between WiFi and cellular when started on WiFi seemed to work just fine without any problems, as did calls that started on cellular, which is promising for anyone who is still eyeballing Project Fi but may also be interested in the Moto X Pure Edition. It's suggested that the Moto X Pure Edition may end up being the first phone to work on Project Fi that isn't a Nexus, and that may very well be the case seen as how it apparently works. When and if Google officially announces this is still a mystery, of course, but getting an account of a first hand experience that Project Fi will work with something other than the only official phone right now is uplifting for those who don't want a Nexus device.