AudioSet by Google - A massive dataset of manually annotated audio events
Vizmato - Vizmato developed by Global Delight Technologies Pvt.
Sketchfab sound - Publish, share & embed 3D & VR scenes with positional audio
Video Merger - Video Merger is a powerful video-merging application, allows you to merge your favorite videos into a single large video by adding background music of your choice.
Note Tracks - Annotated notes for audio content
ROLR - Act out your favorite movies with friends