What app can send international short messages for free?

On Apple's mobile phone or iPad, you can go to the App Store to download an AutoSender, and you can send international short messages. There is no need to escape from prison and the receiver does not need to have iMessage. In addition, you can buy an American or Canadian number in this App, and the other party can reply you by SMS. In this case, receiving SMS is free. The cost of sending SMS/MMS is exactly the same as if you live in the United States or Canada.