Probably nothing that would make a mind map, but ...

Doxygen may or may not work, it probably doesn't understand whatever language iOS uses (objc?). Also I think there are better solutions than doxygen these days.

But if you look at Doxygen then you'll know the kind of thing you're looking for. Note that you do not have to have marked up your code in order for doxygen to produce documentation for you.

Also I think doxygen, and probably whatever is better these days, can produce intermediate output which you could then easily process and produce a mind map on your own, if that's what you really want.

I'd envision this tool rendering larger files as larger bubbles on the screen, showing the @properties and delegate methods as lines between the bubbles, ect