3 things I didn’t know in iOS HIG
Actually four, and all related to bars:
1. On iPhone, be prepared for the change in navigation bar and toolbar (but not the tab bar) height that occurs on device rotation.
2. A tab bar is slightly translucent
3. The status bar is transparent and only its content changes the color (light or dark)
4. A scope bar—which is available only in conjunction with a search bar—helps users define the scope of a search.