Many WhatsApp users could find the messaging app is no longer working on their smartphones as of Monday.
In February 2016, the Facebook-owned service said it would end support for users on the following old operating systems:
- Android 2.1 and Android 2.2
- Windows Phone 7
- iPhone 3GS/iOS 6
WhatsApp users on BlackBerry OS, BlackBerry 10, Nokia S40 and Nokia Symbian S60 will have until June 30, 2017.