... the sound library could probably use an update. At least a third of the sounds I can hear when I type sound more like distressed or in-pain cats than like cute meows. :/ It would also be nice to reduce the volume difference between the different meows, so users don't have to turn the volume down to avoid getting their eardrums assaulted by the loudest meows, and then barely hear the quieter noises. The idea is great though, and I'm definitely going to keep an eye on the addon in case it gets better. In the meantime, well, it's going to stay deactivated. :/ Still giving it four stars, because that's a great idea right there, it's just that the execution could be improved.
(For the people wondering "why it doesn't work": I've noticed that for me, the meows don't start until the pages I type in are fully loaded. If your internet connection is slow, this could explain that.)
I was about to give one star to this app, just like the other commenter, when I have noticed that its really works! But generally, the sounds are discreet, not very loud (with few exceptions) and can be heared not very frequent. I think that's fine, because, otherwise, there is the risck to become annoying. The sounds are not very diverse, (just a few kinds of "miews"), and one of them is quite disturbing, sounds more like a tortured kitten. I think that this should be changed and the sound data base should be enriched.