TL;DR: We hope so. But we don’t know. Currently it is not supported.
Since the Gear Fit 2 had been introduced onto the market, there was a huge demand from users of Sleep as Android that we support it. We saw that Gear Fit 2 is a widely owned device and wanted Sleep to work with it, so we got the device and tried to run our Gear addon on it.
There wasn’t any problem porting the app from Gear S2 to Gear Fit 2. Code-wise, it’s actually the same thing. The same code that runs on the Gear S/S2, runs on Gear Fit 2. So we went on to publish the app on the Galaxy Store.
But oh. It just wasn’t possible. It turned out that as an independent developer, you just cannot publish apps for the Gear Fit 2. Only watchfaces. No apps.
We quit trying at that point, but there are still lots and lots of users who are disappointed that Sleep as Android doesn’t work with their GF2’s. And we won’t deny it, there’s lots of bad ratings for our app as well (we understand that, though it’s not really our fault).
At this moment, there is a ray of light that we might support GF2 over these obstacles after all. We think that it might be possible to build a watchface that will connect to Sleep as Android and work as a quasi-app to gather sensor data. We’re going to try this. Keep your fingers crossed.