Interface

Many of the usernames claimed so far match users' 
@ensdomains. But you know you can claim 1-character usernames too, right? Some are still available.  

p is a good one, so is i.

Your web3 username | Join the chat in /ens

Learn more: ens.domains | Register: app.ens.domains

https://www.interface.social – Explore Ethereum with Interface |
/interface for anything onchain discovery & Interface related

Building /thedapplist | Blue bird - nirbhikjangid.twitter

you mean couldn't find where to claim the username?

you need to create a wallet inside Interface :)