Yes, having a premium account, you can download locally the videos in HD format (only for iOS as of today).
If you want to download a video, you just have to :
- Choose a video and tap on 'start' button :
Now you see the dashboard at the bottom of the screen :
- Tap on 'more' button.
- Tap on 'download video locally'.
- Choose the quality of the video :
The download is in progress :
Once downloaded, you can see all the offline videos in the 'offline videos' menu.