Uberduck is an open-source tool for text-to-speech, voice automation, and synthetic media. It has over 5,000+ expressive voices and can be used to build audio apps in minutes using custom voices and APIs. The tool also offers AI-generated raps and detailed API documentation. Yottaengag, a media company, used Uberduck to create and ship 150,000 custom rap songs and lyric videos for their users in just two weeks.