Viewer for PNG slices?

[JoeLoginIsAlreadyTaken]

I'm looking for software to view the exported RGBA PNG slices.
I had some success by using Slicer (from slicer.org), but this is medical (open source) tool to be used with MRI/CT images, little bit complex to use and the rendering looks a bit artificial.

Do you know other tools to view PNG slices exported from Instant-NGP?

Thanks a lot.