Lovely, but no widget support... Is there any foss weather app with good widget selection? I tried a bunch from F-Droid a while ago and didn't find any.
If you're using the stock F-Droid store app, you have to manually add it. If you're on one of the newer clients, like Neo Store, it's enabled out-of-the-box.
Breezy Weather isn't on the Play Store or the main F-Droid repo. You could either use IzzyOnDroid (different F-Droid repo) or just use Obtainium to get the APKs straight from Github.