Apple News
iOS 9 will bring Quick Reply feature to your favorite Messaging apps
It also included Quick Reply for Messages app, which allows you to reply to a text message by swiping down on the banner notification or swiping to the left and tapping on Reply on a notification on the Lock screen.
If you were wondering why other Messaging apps haven’t implemented the feature then it was because they didn’t have the option for text input action, which was available to the Messages app.
As Rounak had pointed out in his very interesting WWDC 2015 developer notes, Apple has introduced User Notifications Text Input in iOS 9 for developers. It will finally allow developers to implement the Quick Reply feature in their Messaging apps like WhatsApp, Facebook Messenger etc. The Quick Reply feature can be paired with other actions as well.
If you’ve jailbroken your iPhone, then tweaks like Couria, Nuntius, Envelope, TwitkaFly and QuickReplier for Viber bring Quick Reply to some of the popular Messaging apps right now. Couria brings enhanced Quick Reply and Quick Compose to the Messages app, Nuntius brings Quick Reply to WhatsApp, Envelope brings the feature to Telegram, TwitkaFly brings Quick Compose and Quick Reply to Tweetbot and Twitter, and the last one as the name suggests brings the Quick Reply feature to Viber.