Crosstalk is described as 'GoogleTalk, Jabber, and XMPP client for iOS devices. Designed for the iPad, but equally useful on iPhone and compatible with iOS4' and is an app in the Social & Communications category. There are three alternatives to Crosstalk for a variety of platforms, including iPad, iPhone, Mac, Online / Web-based and SaaS. The best alternative is Trillian, which is free. Other great apps like Crosstalk are Monal IM (Free, Open Source) and Boogie Chat (Freemium).
Trillian is an instant messaging app that works on phones, tablets, and desktops while keeping your chats neatly synchronized between all of them! We think conversation should be easily shared between all of your devices, not trapped as text messages on your phone.
Boogie Chat is a FREE XMPP/Jabber and Facebook chat client for iPad. With Boogie Chat you can join multiple chatrooms to talk with several of your friends or colleagues simultaneously. The app supports both single user chat and multiple user chat rooms (MUC).