I still use it, with a DTP-94, for my secondary monitors.
My main monitor is a wide-gamut NEC with its own colorimeter, so I'm less affected by any quirks in ColorEyes.
I don't really know what happened to them - Jack Bingham used to respond to e-mails, but my last e-mail from him was in 2007.
There was an upgrade for the Mac in 2012, but January 2013 was the last I heard of a software upgrade.
Jack introduced an awkward licensing scheme some years ago, presumably to avoid pirating - but I think that the actual effect was to reduce the number of people using the software to below whatever critical mass made it worthwhile supporting. Their website is awful, and hasn't been touched in years. Jack apparently didn't do his own programming, so maybe he lost the actual developer. It's a shame, because he seemed to be quite a leader in colour management, back in the day.