This is my first time usage of the DTube platform, a service trying to bring video to the Steem blockchain. The site is accessible via the d.tube url and it uses your Steem private posting key in order to allow you adding new data to the blockchain as this is needed for uploading videos, or interacting with existing content.
PS: The short video that I uploaded is an promoting video for Vantablack, a revolutionary new material made out of carbon nanotubes, with the amazing property of absorbing 99.99% of photons, giving it the colour close to absolute black.