Android N be possible to reply to a message directly from the notification without having to open the application directly from the notification we can write and send our message. WhatsApp A few weeks ago added support for the Quick answers Android N, but now also will add this functionality in previous versions of Android.
The last version WhatsApp Beta releases rapid response in the notifications. Now when you receive a new message notification we will see in the new answer option. Pressing will show the pop-up notification of WhatsApp own to answer the message to avoid having to open the full application
While Android N will be answered directly from the notification rapid response, in previous versions it will open a pop-up screen to answer to our messages.
Phoneia.com (March 28, 2016). WhatsApp for Android start adding the quick response. Recovered from https://phoneia.com/en/whatsapp-for-android-start-adding-the-quick-response/