UI Sounds - Learn sound design for user interfaces by example 🎵
SoundBetter - Marketplace for musicians and music production professionals
Fugue - Free and premium stock music for your videos, games, and UI
RecordGram - A studio and production marketplace in the palm of your hand
Chill N' Sound - Play and mix ambient sounds to boost productivity
PrimoMusic - An iTunes alternative made to manage iPhone/iPod media files