Want a free way to contact with your friends? Check out WhatsApp Messenger, maybe the iPhone app can meet your requirements.
Want a convenient way to send your SMS messages or Emails on your iPhone or iPad? Apparently you need a nice message app such as the following iMsg.
Want to send some secret SMS massages to your colleagues or close friends? Apparently you need a suitable iPhone app such as the following encrypted message app: Linker.
Many iPhone apps allow you to send message to multiple contacts, but if you want to send same message with different contact names, the Pin-Point SMS message app may be more suitable for you.