It sounds like you may have come across a post or search result related to , a browser extension (mainly for Firefox) used for downloading web videos.
Video DownloadHelper Extra Quality Hot is a premium version of the extension that offers additional features, including: license key video downloadhelper extra quality hot
When converting certain video formats or using the "QR Code" mobile transfer feature, the free version may add a small watermark. A license removes this. It sounds like you may have come across