KEEPVID is a well-known free online YouTube video downloader as well as converter allowing people to save streaming videos to computer. As a result, people are able to enjoy downloaded videos fluently without connecting to the Internet all the time.
Mautic is rare - it is an open source platform with a ton of features. It's also unusual because it focuses on marketing, an industry often ignored by open source developers. Mautic is a marketing automation platform, competing with the likes of HubSpot, Pardot and Silverpop.