Best there is

This app is a bit pricey, but honestly its easily the best there is. Ive tried Palaver (no landscape mode and the keyboard wont minimize properly) Collouquy (hasnt been updated in a year and a half so it doesnt support anything properly) and a bunch of free apps, and this is the best IRC client on the market. It supports landscape mode, you can connect to multiple servers and multiple channels on each server. It notifies you with a non-intrusive color change when theres activity in another channel. You can even turn on/off things like auto-correct and capitalization at the start of setences. If you like IRC, this is the app you want.

Popejewish about LimeChat - IRC Client, v2.16