Whatsapp messaging app has announced that it would stop working on millions of phones around the world by the end of December, as they reach the end of their supported lifespan. This means that users on a variety of older handsets could end up losing access to the messaging app. The Facebook-owned Whatsapp, made the announcement via its support page. The company said that any phone running the Windows Mobile operating system will not be supported after this date. Also, any iPhone running software older than iOS 7 will no longer be supported...