December 31st the world most popular mobile applications drop its support for 'BlackBerry OS', 'BlackBerry 10', 'Windows Phone 8.0' and older platforms.....
"We will no longer actively develop for these platforms, some features may stop functioning at any time,"
-WhatsApp said
the company also said that it will stop working on 'Nokia S40' after Dec 2018. Also, the app will stop functioning correctly on Android OS version 2.3.7 and older, after February 1, 2020.