Article: When the Hulu Plus app is displayed, tap the Free button next to it. Tap it again to install it and enter your password if required.  Now tap the Log In button.

What is a summary?
Tap the App Store button on your device’s Home Screen to launch the App Store app. Type “Hulu” into the search field. The button will turn to Install App. From your Home screen, tap the Hulu Plus icon to launch the Hulu Plus app. Enter your email address and password into the fields provided.