For someone with a little background and just getting started with iOS development, this is probably a pretty good place to do so - reasonably modern, using Xcode 7, iOS 9 and Swift (though mostly 1.x, apart from special mentions). English is not the author's first language (not a problem at all, just an obvious fact), and there's a heavy bias toward storyboard use (entirely enabled by Apple own seeming direction of course, so perhaps not improperly) in a mostly "do this" "type this" style, with occasional exercises that don't require significantly more thought. Swift itself is pretty much relegated to a rudimentary appendix.
He does, however, touch upon most essential and many useful areas - think of it as a working tour by someone who does indeed know his subject matter - and the flow is quite good. The material likely works very well as, say, a week-long orientation.