The client I use for Android is "IRC for Android" (formerly known as "Android IRC").
It's developed by nyt who is an EFNet admin. It's not free, but it's the best.https://play.google.com/store/apps/details?id=com.countercultured.irc4android
You can find him on EFNet in #androidirc
Tip: When using IRC from a mobile device, it is recommended that you connect through a stable IRC proxy known as a BNC. The reason for this is that mobile internet connections are very flaky and will cause your client to frequently disconnect and reconnect, flooding other users of the channels you're in. This often leads to getting banned.
The most popular BNC is ZNC, and it's available for Linux and Windows. A BNC will disguise these connection troubles and will preserve any activity you missed while your mobile device is disconnected.http://znc.in/