Go to the downloader app, paste the copied URL, then click on “Download.” The new page that loads displays the video's title, a preview image, the audio status, and presents your download options. Click on “Download HD Video” or “SD Version.” Choose your download options, then click on “Save. If you want to download video you should use this app:
https://play.google.com/store/apps/details?id=all.video.downloader.freevideodownloader