> The number of classes isn't necessarily indicative of the size

Size, not necessarily, but yes it was in the case (the person was looking at why the binary itself, not any of the assets was above 100 meg).

> or complexity of an app

I'm not sure how 18,000 classes isn't a guaranteed extremely complex app.

Last I heard, Facebook was running into the limits of the Objective-C runtime because they'd register a bunch of classes at startup and overshoot their launch time. They factored a bunch of stuff out into dynamically loaded frameworks off the startup path or something like that.