I've seen it, but it's nothing like even Quasseldroid. And quasseldroid is already a horrible codebase (mostly because I took over maintenance when I knew nothing about code quality).
Yet even Quasseldroid manages to be better.
That said, there is truly a need for a really good, FLOSS irc client ob mobile.
You're saying they're nothing like each other but are providing no examples. Besides one being an app and one being a website, what are the differences? Neither quasseldroid or Lounge have push notifications or searchable messages yet, so they seem to be pretty identical feature-wise.
EDIT: and we aren't talking about code-base, are we? If so, Lounge's is pretty solid (although it is in a pretty constant state of transition from ES5 -> ES6)
Quassel has them, doesn't mean Quasseldroid does :P
And I don't think you can say due to it's nature it's faster... I run Lounge in 20+ active channels on my iPhone SE and it runs perfectly. Native != more performant (and if the code base is as bad as you say I wouldn't expect it to be).
The bad part of the codebase is bugginess, and RAM usage. Especially because it always keeps all messages in RAM.
But what I consider a bug is already the best case scenario for the web client.
And 20+ active channels is nothing.
I'm in 460 active channels, with combined 40'000 users, and I get about a hundred to 200 messages a minute, while using the app on 64kbps connection.
(That's my test case for what should usable)
And quasseldroid already has code for those two, and a rewrite is almost done, I'm just waiting for the core changes to happen, and then release version 2.0
Yet even Quasseldroid manages to be better.
That said, there is truly a need for a really good, FLOSS irc client ob mobile.