Last time I tried tracing someone this way it worked (:-)) so lets do it again…
Dan Switkin long ago wrote ImageViewer, which IMO is rather superior to ShowImage. I was going to make it available on BeShare, but I found his website is still active, and there he makes a strong prohibition against mirroring the app! I suspect he no longer really cares (the site seems to be static since 2008) but the emails he gives there are defunct.
He now seems to be at Google (or maybe moved on to Oculus?), but the one email I found for him there is also “disabled”.
So if anybody knows him, and could get in contact, that’d be great!