I agree with everyone that the skill buttons on the iphone interface are too small. I kept trying to press them, but missing them and then dying in battle. Even the auto attack button is too small. I kept trying to press it and instead my character would try to walk to that spot on the screen.

Regarding the "your friend is online" banner, it would be useful if it said which friend, but just telling me that a friend has come online is completely useless as I have over 100 friends, and 20 or so online at any one time. So the banner keeps going off every 20 seconds or so. A better idea would be to add a line in the regular chat window, perhaps a different text color, that says "[character name] is online". Then it won't take up any valuable screen space.