Kik Messenger is a free smartphone to smartphone messenger, similar to BlackBerry Messenger but cross platform. Kik Messenger can be downloaded to most BlackBerry, iPhone and Android devices.
You can message your friends while avoiding carrier fees by using your data plan. Since you have removed the SMS messaging capabilities only people who have the Kik Messenger application can receive Kik messages. Each Kik message that is sent uses a very small amount of data, less than 1 KB per message.
Kik Messenger uses data to send messages so any roaming data charges from your carrier would apply. It helps to use WIFI whenever possible but Kik also works on 2G and 3G networks.
To download Kik Messenger, go to www.kik.com/m on your smartphone and your exact device will detected and your download will begin shortly.