I just went back to check now since I've been reminded of its existence, and I haven't completed it. I'm missing one from Daisy, and another from Koga. I'm sure Bulbapedia or another website has answers to the Fame Checker, but I'm not going to bother trying to complete it, since I don't think there's even a reward for it. I haven't been playing my LeafGreen in a long time anyway, so it's pretty pointless for me to do that.
Now was the feature kinda interesting? Yeah, I learned a little bit more about those in the Fame Checker, but otherwise, it was just something that was optional, and kinda forgettable unless I was searching through my bag. It's not as pointless as the Techy TV, but they were just dumb inclusions that didn't move the game along at all. The fact I have that habit where I talk to every NPC as much as possible kinda helped in filling it out as much as it has, but again, I wasn't actively searching for the facts.