App launches and is stuck on "logging in"

This means that sometime in the past you enabled "autologin" (but don't have an acccount and left it blank).
First force quit the ooTunes app:

1. Press the home (the circular front) button on the device (to leave the app you're in).
2. Double-press the home button and a list of recently used apps should appear.
3. Tap and hold the app icon until they start wiggling.
4. Tap the red "-" on the app you want to quit.

Then go to "settings" on the iPhone, in the "ooTunes" section, turn OFF "autologin" and then launch the app again.