Bashupload - Upload files from command line to share between servers
Snarl - Snarl is a notification system for Windows.
FilePizza - Open source application used to transfer file via WebRTC and WebTorrent.
Notifu - Notifu, a free open source pop-up balloon utility
BlackHole File Transfer - Blockchain-based file transfer. Designed for everyday use.
Notify OSD - Canonicals on-screen-display notification agent, implementing the freedesktop.