Not really ready for prime time use. It crashes waaaay too often to be useful. Even on my iPhone 6+ it crashes. The other problem is that it is very slow to load images and very choppy. I cant believe they used to charge money for this app. I dont know if its not technically possible to get these to work on phones (they are gigapixel images, after all), but it isnt working on this version.
Xanthines about Aperio ePathViewer for iPhone