Spotify has launched a new feature for premium subscribers that makes it easy to sync your entire library for offline listening. Now you can sync your whole library in one single tap. This feature went live on the Android version of the app recently and now it is also available for iOS in the latest update of the app. When you go to the “Songs” tab, simply tap the “Available Offline” button. Spotify will sync up to 3,333 songs and they will be available offline for 30 days. This feature is only available for premium users.