The add-on is supposed to download videos on the internet for you. However it edits and modifies those videos during the download process to include a QR code advertisement that takes up to 1/4 of the available video space. This QR code advertisement links back to the add-on's webpage. This advertisement is not listed or mentioned in the add-on's description prior to downloading. This is a relatively NEW addition to the add-on within the last year.
UPDATE: now the app doesn't work on Youtube, utterly useless.