Since the new format, playing Duel on my iPhone has been glitchy:
1) Quizzes quite often freeze (2-3 per day), requiring a refresh and thus the reloaded quiz penalty.
2) page size is fixed and canít be changed. This requires some scrolling/jockeying of the screen to be able to see question and all answers, but then canít see the correct answer and interesting information. This increased need to scroll no doubt contributes to #1 above
I recall the previous page format had a ďmobileĒ screen selection that worked well.