I'm a long time Spotify user and have been waiting, giving Spotify a chance since January when I bought this watch. If this simple and obvious update to the iWatch App to allow for offline music listening isn't addressed soon, I too will be forced to switch to Apple Music. That will not allow you to play Spotify in a manner that you want to use it, Spotify and Apple are still trying to come to terms where Spotify can stream to the Watch over cellular. You can use Apple Music (which I use when I use the part trail) or Pandora but not yet Spotify. I'm a long time Spotify user and have been waiting, giving Spotify a chance since January when I bought this watch. If this simple and obvious update to the iWatch App to allow for offline music listening isn't addressed soon, I too will be forced to switch to Apple Music.
Apple Watch Spotify Offline Mode
Spotify is one of the best music streaming apps out there with availability across all major platforms. It's paid Premium subscription makes it even better to use as it brings offline playback alongside many other features. But the one major downside of Spotify is that it does not have an app for Apple Watch which means you have to rely on your iPhone to enjoy music on the go. And this is what going to change pretty soon as there's a new watchOS app named Spotty that will be the solution to this problem.
Spotty is an Apple Watch app which allows you to sync your Spotify playlists with the Apple Watch and listen to them even when offline. The app works all models of the watch and is currently in beta with plans for public release in early February which is this month. While the app is and will be completely free for download, the user should have a valid Spotify Premium account to use it.
Once you have installed Spotty on your iPhone and Apple Watch, you will need to launch it and grant permission to access your Spotify playlists and songs. The next step is to enable the toggle for syncing feature which will start syncing all of your songs from the Premium account to Spotty app on the Apple Watch. The good thing here is that you are not bound to keep the watch on charging to start the syncing process which is something users have to do with Apple Music.
The iPhone app of Spotty packs in various settings which allow you to personalize the app behavior. You can choose the music quality for syncing purposes, enable/disable gestures, Siri integration, and start a workout right when you start a playlist. The app supports shake and chop gestures for changing songs faster.
As for the playback on Apple Watch, you can choose to listen to song either directly from the watch or use the Spotty app as a remote control for controlling the playback on your iPhone (known as tethered mode).
Apple Watch Spotify Offline
Here is also a video from 9to5Mac folks showing an overview of the Spotty app on Apple Watch: