VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.
AIMP - AIMP : Free Audio Player : Официальный сайт программы
Sli.do - Slido is the ultimate Q&A and polling platform for live and virtual meetings and events. It offers interactive Q&A, live polls and insights about your audience.
foobar2000 - An advanced freeware audio player for the Windows platform.
Mentimeter - a web-based polling tool for workshops, conferences & events