So far, all Karaoke apps offer rerecorded backing tracks because the original recordings are usually kept sealed. There's a new app now on the market for those who want to be backed up by the real tracks when they dream of stardom. It's called Hook’d. It started on July 10 as a free app for iPhone and iPod Touch and offers 42 original backing tracks of hit songs. Unlike singalong apps that play covers — renditions of hit songs rerecorded by anonymous studio musicians — Hook’d features everything from the original recording except the voice track. The software developer who created Hook'd negotiated with the three major recording companies, Warner Music Group, Sony and Universal Music Group to get permission to use the original recordings. The app also shows the lyrics on the cellphone screen, above the image being recorded as you sing. And if you want more guidance, you can listen to the original lead vocalist. Hook’d builds on technology from MuseAmi’s first app, ImproVox, introduced in 2010 to help singers who probably should not perform outside the shower. Real-time digital signal processing corrects those who are off key. Hook’d also has other studio effects that users can apply before they share their performances on Hook’d’s YouTube channel or on Facebook and Twitter.