That's an interesting question. There is one thing that is unique to the Edge Magazine app on iOS, though. Zip archives of the magazine do not contain just pdf

That's an interesting question. There is one thing that is unique to the Edge Magazine app on iOS, though. Zip archives of the magazine do not contain just pdf files, but also bunch of high resolution game screenshots. Those screenshots can be seen in the app by clicking the gallery button in a several places. The gallery button link is in the form media://image.jpg, which probably means that the application registered custom protocol handler and handles it by displaying image on top of the magazine itself. That's the way to recognize iOS version, but I'm not sure if Google Play Newsstand has the same feature.