Components
DTube is a decentralized streaming video platform linked to Steemit (the decentralized social media) which allows users to upload videos easily and make money (or cryptocurrency) through the upvotes on their post.
Proposal
I have seen a proposal for the download feature but my own proposal is the save offline feature. Moderator please note that there is a difference between download feature and save offline feature as the dowload feature saves to the phone storage while the save offline saves to the cloud storage.
Mockups / Examples
This feature should be added to the options tab
once a user taps on the save offline he can choose the quality of the video to save as the mb required will be shown like in YouTube 
Benefits
The main benefit of this feature is that it allows users save their videos to the cloud storage and watch it later. These videos can be accessed by the user at anytime and on any device as long as he or she logs into the Dtube site or app. This feature allows users to watch heir videos again as it doesn't require data to watch them once they have been saved.
Posted on Utopian.io - Rewarding Open Source Contributors