Growl for Windows - Growl for Windows is a Windows-compatible version of https://alternativeto.
Tumbleweed - Daily videos of people sharing their POV on today's issues
Notify OSD - Canonicals on-screen-display notification agent, implementing the freedesktop.
Whale - Video Q&A with influencers and experts 🐳
Notifu - Notifu, a free open source pop-up balloon utility
FireRTC - FireRTC is the easiest way to call from your computer for free