That is, Pop Mech's Interactive Edition isn't the first "issue" of monthly apps - those won't arrive until later this year - it's more of a tech demo that mixes up older and newer material to show how they're thinking about a digital magazine. (Fortunately, it's just $2.49. I doubt this price will stick.)
It's essentially the same app I saw a couple months ago, which is mostly a good thing. It's down to a mere 27MB package - compared to 500MB for the similar Wired app. Video clips are seamlessly integrated with the page. (Though a couple, like the video for the article "Epic Air", were choppy and froze.) The neato interactive earthquake app, showing a wealth of data from the USGS, is built directly in the mag now.
Its colour-coded navigator, for quickly skimming the entire magazine, is perhaps my favourite table of contents in an iPad mag yet (seen above). Except for the occasional moments when the app breaks its own navigational scheme - typically, swipe left-to-right to go to the next page - it's fairly easy to use, taking care to explain interactive wonkiness when it arises without feeling too forced. Which is more than can be said about some mag apps.
It manages to mostly walk the line between being a "magazine" and some glimpse of the future of slick digital content you might pay for, though it never quite escapes that sensation of requiring "work" to read, versus leisurely flipping through a magazine. Which is the feeling I hope digital magazines really learn to mime in the end. Zippy videos don't replace the feel of high quality, glossy paper between your fingers. (Ironically, for the moment, my favourite iPad reading experiences are Instapaper, Reeder and BoingBoing's slick web features.)