CasterSoundboard - A soundboard for hot-keying and playing back sounds. (For podcasting)
SoundNode - SoundCloud desktop app (OS X, Windows, Linux)
Soundpad - Play sounds in voice chats in high digital quality.
Soundbar - A lightweight SoundCloud player for Mac
Soundboard Studio - Soundboard Studio lets you take your podcast, live show, gig or performance to the next level.
Sleeve - Your currently playing track displayed right on your desktop