2 tips today, but about Finder.app rather than iOS app development :)
If you hit
F5in Finder, the last item in the current directory will be selected and Finder will scroll to it. This should work with most function keys, but it seems like all of them will beep except
F5. This selection and scrolling behavior puzzled me for years until it was explained to me: it's just Finder searching for a match alphabetically. If no match is found, it selects the last item and scrolls to it.
cmd+shift+.to show hidden files in Finder.