This is a good extension for downloading a video but sometimes all it takes is the video without the included sounds and it is kinda suck. I did installed the latest version and all necessary related files but still have problem with the issue I encountered.
In early 2018 Ant Video Downloader worked great 90% of the time, even on obscure sites. Currently (Feb 2019) about 50% of videos can be downloaded. This occurs even on the same website, ie Youtube some can be downloaded others cant, and happens a lot with more obscure sites. Also note that VLC media player is often needed to play the formats the videos are downloaded as.
Please note that Native Application is only contain configuration files and required dependency libraries for streaming video support. You can check installer with any anti-malware soft to make sure it is totally safe.
By default all downloaded files will be saved to "Ant Videos" folder in your system "Downloads" directory. You can change this path at AVD tab under the Downloads section same as path to temporary files.
We continue to work on migration AVD to a new Firefox. You still can install old AVD version in Firefox 56 and below from Mozilla website here: https://addons.mozilla.org/en-US/firefox/addon/video-downloader-player/versions/