Hello! Messenger Free for iPhone - Hello! is a free cross-platform instant messenger. It lets you chat with all your friends anytime, anywhere, reducing expensive SMS fees. Besides messaging, Hello! includes many other useful features, such as group chat, message delivery confirmation, landscape chat, photo exchange, Facebook status updates, push notifications, and many more
ChatNow Pro for Facebook - This app is a fast messenger which allows you to chat with your Facebook friends while on the go. The user interface is specially designed to let you easily communicate with buddies from your iPhone, iPod touch, or iPad.
The application uses Facebook OAuth authentication with official Facebook SDK
GroupMe for iPhone/iPad - GroupMe is the best way to chat with everyone you know. It's absolutely free, whether you are talking to a group of friends, or texting with one person. Best of all, it works on nearly every phone, via push or SMS. With GroupMe, it's easy to reach anyone, anytime, anywhere
Versagram - Versagram lets you create beautiful graphical text messages and share them via Instagram and iMessage.
The app is constantly updated with new text themes
Textie Messaging for iPhone/iPad - Textie Messaging lets you message free between iOS and Android devices. You can send messages to any other Textie user, any email address, and even to most U.S. mobile phones. Replies come straight back to the app, so you can use Textie with anyone, whether they have the application installed or not
MessageMe for iPhone - MessageMe is a cross-platform instant messenger which allows you to stay in touch with people you care about using your mobile phone.
With it, you can chat with friends and family for free over a WiFi, 3G, EDGE or LTE connection
Colloquy is a full featured IRC client for iPhone, iPod touch, and iPad. It is built built atop the powerful Chat Core framework, same as its popular Mac OS counterpart. Colloquy for iOS is optimized for mobile use and supports multitasking, push notifications, and more.
· Convenient nickname, emoticon, IRC commands completion popups
Talk.to for iPhone/iPad 2.6. - Talk.to is a free instant messenger which lets you chat with Facebook and Google Talk friends, and with co-workers using Pingpong.
Talk.to is cross-platform and is also available for Windows, Mac, Linux and Android
HipChat for iPhone/iPad - HipChat is a cross-platform instant messenger that allows you to have persistent group chats with your coworkers.
HipChat is designed for companies and teams who need a simple way to collaborate with clients and colleagues.
HipChat features persistent rooms and 1-to-1 chat, complete chat history, file sharing, SSL encryption, emoticons, etc
iTalk Messenger Lite - iTalk Messenger is an instant messenger that allows Peer2Peer communications between iOS devices. As long as you are connected to a router or access point with WiFi enabled, you will be able to chat with buddies who are connected to the same access point.
Besides WiFi, the app allows you to chat via Bluetooth
