Adding WebSockets to npub.cash was a bit less trivial than anticipated, because all sockets need to be authenticated. But I am pretty close to finalizing the integration.
Here is how live updates of incoming zaps look like in cashu.me:
https://blossom.primal.net/3e93b03e594316bb1709620712f1a27f98da11b2e6a51faedcd60bdc804ce5ce.mov