A few ideas that might be of your interest:
* Automatic text shrinking in UILabel is likely the numero uno bad feature put in place to encourage bad interface design. It makes font sizes inconsistent, it destroys visual rhythm, and it jags the lines. Try to implement variable height table views and be typographically consistent.
* UIActionSheet on iPhone should be presented from the bottom-most edge of the screen, not any random view, and not from the bottom of a view above the toolbar.
* The Comments view is using the grouped style with one cell per section. This is not a good idea because it simply introduces much more visual noise.
* Readability integration, read-later services and social sharing are all present in news:yc. They are not actually selling points when everybody can get it done practically in no time.