I downloaded the paid version of app onto iPad and uploaded my songs no problem! I also downloaded the app onto my phone but only the free version is showing,do you have to pay for it on separate devices?
Go into settings on your iPhone, then scroll down to In App Purchases - click it. When the window opens, there is a button at the bottom that says "Restore Purchases". Click it and your license will be available on your iPhone as well as your iPad.