Facebook-owned messaging app WhatsApp has started phasing out support for Apple devices running iOS version 7 and older, the media reported.This would not affect people who already have WhatsApp installed on their iPhone 4 devices as it should continue to function till 2020, but users would not be able to re-install the app if deleted, the Mirror reported on Thursday."For older iPhones, the app would not get any new features and updates anymore and it is also possible that some already existing features may stop working," said the report.In a previous blog post, the company had claimed that the messaging app would stop functioning on iOS versions 7 and older after February 1, 2020.WhatsApp has already stopped serving devices running on Nokia Symbian S60, BlackBerry OS and Windows Phone 8.0 and older.The company would withdraw app support for Android versions 2.3.7 and older after February 1, 2020.