The safest place to download the free WhatsApp Messenger mobile application is the official app store for the mobile device on which it's to be downloaded. Android device users can safely download WhatsApp from the Google Play store, while iOS device users can download WhatsApp from the iTunes App Store.
WhatsApp Messenger is safely available for download on its official website, WhatsApp.com, for Android, Blackberry, Nokia Symbian and Nokia S40 platforms. Microsoft's Marketplace offers the Windows Phone version of WhatsApp Messenger for free. Users should avoid downloading applications from untrusted or unknown sources, as the likelihood of acquiring unwanted spyware, viruses and other malware is high.