I purchased the Pro version. After a while it stopped working and displays: "Youtube switched to separate audio/video streaming technology for higher quality formats and no longer provides direct 720p (Since 24 September 2018)/1080p/mp3 streams. Converting these streams to downloadable formats for you needs powerful server infrastructure, therefore 1080p/mp3 downloading has been limited to PRO users. Read more at - https://videodroid.org/pro_upgrade.html. FREE users can download all formats in CACHE where some PRO users fetched the video/audio in past 24 hours, to test the feature you can try downloading popular videos."

When I go to their website, under support this is all you get: "Usage of this website and all provided products is subject to compliance of your countries legal permissions, if your local laws do not permit downloads and audio conversions of online videos you are not allowed to use this service. You are also not permitted to use this utility to infringe any sort of copyright by downloading multimedia content which you don't have rights to use or is not open-source." -- That's it. They display this blurb and nothing else. There is no support. So if you purchase this add on, there is nothing you can do if it fails.

Update: On the advice of the developer in the comment below I tried the new version. It downloads 0 bytes. Still "1" rating.

Update: A week later it downloads but not in HD. It asks me to upgrade with another $30. I just did recently, apparently it does not remember. Still 1 stars. For all the annoyance, and considering I paid for it, if I could I would give it 0 stars.