Spotify has been a part of the Samsung Gear since the Gear S2. What's been missing since then, is a way to listen to music right off the Gear without a connected smartphone and without needing a connected smartwatch. This is where offline playback comes in. Now you'll be able to download certain songs or playlists to the Gear S3. To use it, you'll need to first download a Spotify add-on app that can be downloaded from the Gear Manager app from your smartphone. After that, you'll be able to choose which playlists, songs, or albums you want to save to your Gear...
Source: http://www.gsmarena.com/samsung_gear_s3_gets_spotify_offline_playback-news-25749.php
