BookWidgets - BookWidgets is an excellent application that let you create engaging exercises in minutes and easily share a varied variety of beautiful and fun activities with your classroom and others.
Growl for Windows - Growl for Windows is a Windows-compatible version of https://alternativeto.
Padlet - Visual boards for organizing anything.
Notify OSD - Canonicals on-screen-display notification agent, implementing the freedesktop.
Socrative - Socrative helps teachers engage the class with educational activities to measure and visualize...
Notifu - Notifu, a free open source pop-up balloon utility