Pennywise - Cross-platform application to open any website or media in a floating window
VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
PiP for Mac - Always on top window preview similar to the popular windows only OnTopReplica
AIMP - AIMP : Free Audio Player : Официальный сайт программы
Shopify - Shopify is a powerful ecommerce platform that includes everything you need to create an online store and sell online. Try it free for 14 days.
foobar2000 - An advanced freeware audio player for the Windows platform.