IDM (100% integrated)
Until the previous version IDM wasn't completely integrated with Vivaldi but with version 1.13 they solved that problem.
I mean that before I had to open a second window to bring up the IDM dialog box and be able to download any video.
thanks Vivaldi team
Not completely, but almost there! I noticed that download button is appearing more, but out of sync with the download source, window, audio or video. Anyway, they're improving more and more!