If you use weechat, then weechat-android is probably the best Android client available. I've been using this for over a decade is probably the one of the main things preventing me from even considering iOS (which does not have a weechat client... yet).

Otherwise, I've know people who have had success with TheLounge as a PWA. Of course, there is IRCCloud, which is a more polished but proprietary version of the TheLounge and has been around for a long time.