Hi @nokturrduk84, you can install it in Opera, just install one of two extensions: "Extension source viewer", or "Download Chrome Extension", that allow you to install extensions from the Chrome Web Store, and then install the "Video DownloadHelper" extension.
Alternatively, you can try one of the following extensions for Opera:
"Video Downloader Pro".
One more thing: When I'm downloading something with Opera & then I forget about it & hit on "Exit" button, it closes normally (doesn't remind me that I'm downloading the file). So, sometimes it's a problem for me. Is there something changed in my Opera settings, or you guys removed this reminder? If, so, please bring it back in options to choose if someone wants to enable that notification or not.