Is your feature request related to a problem? Please describe.
Animated PNG (APNG) is an extension of PNG and uses the same file extension (.png) and MIME type (image/png). An example APNG is a bouncing ball animation by Holger Will. The zune-png crate that Oculante uses doesn't support APNG.

Describe the solution you'd like
I would like to open APNG files as if they were GIF files. The png crate ((docs and crate page) seems to be about as fast as zune-png now.