Replace "youtube" with "ssyoutube" in the URL to download the video in any quality available.
Replace "youtube" with "nsfwyoutube" to bypass age restriction.
Replace "youtube" with "youtubeskip" in the URL and you won't see ads.
Replace "youtube" with "listenonrepeat" in the URL to repeat the video automatically .
Replace "youtube" with "gifyoutube" in the URL to convert video into gif format .