Tappr.tv lets iPhone and iPad users create customized music visualizations--think lights and effects that appear in time with the music. Users can then share their creations with the rest of the Tappr.tv community.

Version 5.0 of the app hit the iOS App Store this week, and Tappr.tv creator Deeje Cooley was on hand at Macworld | iWorld's Mobile Apps Showcase to demo the latest release.

Tappr.tv lets allows users to create their own unique visualizations to go with songs already in their music library. You can watch and rate visualizations made by other users who have the same songs in their music library

"Music visualizations are algorithmic; I wanted something more interactive," Cooley said, adding that he had been working on the concept behind Tappr.tv for 15 years but that it just wasn't feasible until the iPad came along.

With Version 5.0, Tappr.tv will now respond to users' voices in addition to their touch. Cooley said that he hopes to be able to add the ability to remix other users' songs in a future update.

Tappr.tv is compatible with the iPad, iPhone, and iPod touch. It's a free download in the App Store but there are optional in-app purchases available for users who want more visual wands for their creations.