I can see all the functions on my iPhone just fine and for instance, the letters in the USA Today app are just fine for reading. Certain apps, like iShoot, A 100 Pushup Workout Program and iStethoscope use such tiny letters that they make it hard to read them.
So maybe I am posting this more to get developers to listen up and use larger font sizes. I know I am not the only one concerned about this issue.