What are some alternatives?
When comparing HearSeeParty and Photomosh, you can also consider the following products
Glitchatron - Destroy your favorite photos
MVGEN - Make your own music videos with audio, gifs, and special effects
Glitch Wizard - Create trippy glitch photos and animated GIFs
Tumblr Music Video Generator - turn Tumblr accounts into music videos
Decim8 - Turn photographs into glitch art
Gif Sound - Combine Gifs and audio