Yes! Our mobile app allows you to download individual courses for offline use. To do this, go into the course you'd like to download, and click the download icon in the upper right-hand corner. From there, you can then tap the "offline courses" button on the main courses page to view the courses you've downloaded.
You can have a maximum of six courses downloaded to your device at any given time, and they'll remain available to you until you either delete them from your device, or your subscription expires.