My UI designer favors a radio style button for Yes/No. I understand there is no such UI component in iOS and I would use two different custom images for normal/highlighted state. However, what I need to know if Apple would allow me to do it. Is there any clause in the human interface guideline against using radio style button instead of SegmentControl style? Help would appreciated, thanks
DONT! This really is something you should avoid under pretty much all circumstances. The Apple GUI team has designed a different control for such task and you should rely on the fact that they really did a great job. Keep in mind that the user is using his finger to use the UI and that a radio-button is more or less designed for a mouse cursor. The "circles" would need to be huge to be properly addressable with a finger. Apple recommends 44points square for any touchable control.
Apart from that, you will not get rejected for creating such custom control.