See this FYI from Opera about the long approval time. Hopefully Opera will sort that out. https://forums.opera.com/post/128215

Is this the Firefox version you're talking about? https://addons.mozilla.org/en-US/firefox/addon/easy-youtube-video-download/

If so, you can keep an eye out in https://chrome.google.com/webstore/category/extensions for the Chrome version, which you can install in Opera using the method I mentioned previously. I don't see it in the Chrome web store yet, so have the FYI you when it's ready.