ilifeTouch is building two apps that are going to use the words Menubar or Statusbar in them.
Which name is correct and what is the correct way to spell that name?
Well, the menu bar is always
the menu bar: the single strip all across the top of the screen with the Apple, File, Edit, etc. menus.
Generally speaking, a "status bar" could be any rectangular area of the screen that displays the status of something, like the one at the bottom of Safari.
But technically speaking, there is a special class of "
status bar" that holds "status items." Confusingly, there is only one of these in OS X, the system status bar, which is always at the right side of the menu bar. Theoretically, Apple could enable others, but right now this is not supported. And this is developer-speak; only people who read the developer docs would understand this special use of the term "status bar." That is why the developers would use the term.
So when talking to users, just refer to the menu bar.