I don't really keep track of those things, but I can give you two attempts without much searching:
just this week I saw https://adamant.im
There was a thing called "my echo" (which appears to have failed/been cancelled).
just this week I saw https://adamant.im
There was a thing called "my echo" (which appears to have failed/been cancelled).
Other related things are fine: e.g. mapping public keys to human-readable identifiers like a nickname is a good match to what a blockchain is good at, I get why people like the idea of cryptocoin-payments in a messenger platform, ... Still leaves the general concern of "does this really need it's own coin with an ICO and hype", but at least the ideas make some sense there.