Adds a download button to tiktok.com/@profile/video pages. Click a video, the icon is added by the social media share buttons. Right click the icon, and save as. Left click takes you to the video in your browser.
This adds a download icon next to the share icons on a tiktok.com/@profile/videos/ window that pops up after you click a video. Right-click the icon and Save As... to save the mp4 video file to your hard drive.