iMessage Features - iMessage allows users to send texts, photos, videos, contact information, and group messages over Wi-Fi or 3G to other iOS 5 users, thus providing an alternative to standard SMS messaging for all users with devices running iOS 5.
iMessage is accessible through the Messages app on either an iPhone, iPad, or an iPod touch. Owners of these devices can register one or more email addresses with Apple, and, additionally, iPhone owners will have registered their phone numbers with Apple.
A user can see if the other user is typing a message. Three pale blue dots/circles appear in the text bubble of the other user when a reply is started. It is also possible to start a conversation on one iOS device and continue it on another. iMessage-specific functions operate only between iOS 5 devices, such as an iPhone or iPad, but, on the iPhone, iMessage can use SMS to communicate with non-iOS devices, or with other iPhones when iMessage is unavailable.[2] On iPhones, green buttons and text bubbles indicate SMS-based communication; on all iOS devices, blue buttons and text bubbles indicate iMessage communication.
All iMessages are encrypted and can be tracked using delivery receipts. If the recipient enables Read Receipts, the sender will be notified when the recipient reads the message.
iMessage also allows users to set up chats with more than two people - a "group chat".
