You must establish a connection between gbXRemote and GarageBand the first time you use it. First, make sure GarageBand is running. Open gbXRemote, tap on the info button in the top tight corner, then press 'Connect'. The next screen will show the computers where you are running GarageBand (typically only one). Tap on that text and a checkmark will show. Exit the info screen.
On the GarageBand computer screen, a popup message says that it has detected a new OSC device and asks if you want to add it to the setup - click the 'Add' button. After a few moments, the gbXRemote screen should populate with your song data. If the track name is not showing on the Main screen, tap on the left or right arrow keys on the Main screen and the screen data should all fill in. Also try going to the other tab screen options - EQ and Master - then return to the Main screen.