I am an adult, beginner guitar student. When asked if I was to learn to note-read sheet music for the melody, I said yes. The books for note reading all seem specific to your instrument, but I really wanted a way to accelerate the memorization of written note to knowing the note in my head and my hand. So, I checked several applications in the store, and picked this instrument-independent one.
First, it is iPhone, but works fine in x2 on the iPad, under both iOS4 and iOS5. Second, it has Beginner and Advanced user levels, with beginner sticking to notes near the common staff lines and Advanced extending beyond. Third, you can focus on Treble, Bass or Both.
The App is a timed drill, defaulting to 60 seconds but settable to other lengths. It scores you based on number correct and incorrect and keeps track of your best score.
Great value for the cost to download. Would love to see and iPad version, too.
Update after playing awhile
Many of the notes from Level 4 on are not common on the guitar, and base clef is not relevant. App should have some customization so you can set instrument range for notes.