WhatsApp will be missed by iOS 8 users starting from 1 February 2020 because of an update from instant messaging platform hence iPhone users are to upgrade to a new version of the operating system.
iPhone users are recommended to upgrade to the latest iOS available for your phone on the apple store for the best experience on your phone. If you are using one of these devices probably you need to upgrade: iPhone 4S, iPhone 5C, iPhone 5S, iPod Touch Fifth Generation, iPad 2, iPad with Retina Display, iPad Air, iPad Mini and iPad with Retina Display
“For the best experience, we recommend you use the latest version of iOS available for your phone,” said WhatsApp
To be able to use WhatsApp on your phone you’ll have at least iOS 9, The good or better thing is that having iOS 9 is easy you just upgrade from you apple store and it’s free.
“We don’t explicitly restrict the use of jailbroken or unlocked devices. However, because these modifications might affect the functionality of your device, we can’t provide support for devices using modified versions of the iPhone’s operating system,”