Ok, I tried the latest version of XnView, and I found it works with iPhone app PNGs. Howeever not all the files of this type work.
I created a zip file containing certain iPhone PNGs that still do not load in XnView, and uploaded this to mediafire for you to download and use to debug XnView.
http://www.mediafire.com/?sg22ykhrzgjxzq4
Please fix this bug.
Not all iPhone format PNGs work
Moderators: XnTriq, helmut, xnview
Re: Not all iPhone format PNGs work
Have you managed to fix this bug yet?