Does not work for me

Sorry to say this app is useless if you own an iPad Wifi. It says its compatible, which is why I downloaded it, but my iPad doesnt even show an icon. My iPad is synced, the icon shows up in my iTunes account, but no icon on the iPad. Please tell me what Im doing wrong. I leave for Kauai in one hour!

Bound for Kauai about Kauai GPS Tour Guide