WhatsApp - coming changes
You will soon be able to send and receive WhatsApp messages on up to four synched devices. Currently, the only other way to do this is by using the Window's WhatsApp web program that enables you to send and receive messages on a PC. This is only possible if your phone is switched on. The new capability will work even if your phone is turned off.
Another feature that is on the way is 'View once', this will delete any communication after it has been viewed. There may also be an iPad app.