WhatsApp for on iOS is used to sell for $0.99 which became free now. But it is not entirely free, it is free for first 12 months and after that period an annual subscription kicks in at $1/ year. This brings WhatsApp on iOS to inline with other mobile operating systems including Android, Windows Phone, BlackBerry etc. WhatsApp for iOS also got an update today with some new features.
Along with the free for one year offer, WhatsApp updated to version 2.10.1 on iOS. This update brings chat backup support to iCloud. Now it is possible to take a backup of all your chat history to iCloud, that way you won’t miss any chat messages. To enable the chat backup go to WhatsApp > Settings > Chat settings > Chat Backup.
Another useful update in this version is a multi-send UI, this allows users to send multiple photos at the same time.
In this update WhatsApp added a URL schema support for 3rd party apps, using this developers of other apps can now interact with WhatsApp on iOS. WhatsApp is the most popular messaging application right now and available on all major mobile operating systems, and with increasing popularity developers want to tap into that potential.