Sayonara - Linux audio player and music library manager
Mockuuups Studio - Fast and easy way to create product mockups on macOS, Windows and Linux.
Mopidy - Mopidy is an extensible music server written in Python. Mopidy plays music from local disk, Spotify, SoundCloud, Google Play Music, and more. You edit the playlist from any phone, tablet, or computer using a range of MPD and web clients.
Mediamodifier - Create beautiful designs and product mockups in seconds.
Untrack Me - Surf the web, free from tracking
mockDrop - Is a webapp for creating free device mockups including your screenshots.