Among some other select apps, WhatsApp was yet to be fully optimised for Android Nougat, especially with the new notification panel. However, with the beta update v2.17.13, the app is now fully functional and optimised. First spotted by Android Police, the app now also takes full advantage of the new Android Nougat features. 
Taking an example, now you can see all the messages from a single conversation and can also reply. While the Quick Reply function was there in previous versions as well, the app would only show the latest message from a conversation. For instance, if you have received a bunch of messages from a friend, the notification panel would only show the last received message. Also, the ‘Quick Reply’ option would not disappear after you receive some more messages from that particular conversation.
Other than this new addition, Android Nougat can display all the messages from all the conversations right inside the notification panel. Also, as mentioned above, you can reply individually to each conversation from the notification panel itself. This functionality is also available from lock-screen but you would need to put in your Password or fingerprints if set any, in order to reply.
WhatsApp, probably the most used chat messenger, has been getting in some kind of security hiccups here and there. After all that went between Facebook-owned chat messenger and Delhi High Court, WhatsApp was recently accused of playing around with the end-to-end encryption and can sometimes leave the messages open to intercept. On the good side, the company introduced the much-anticipated video calling feature to its ecosystem last year. And for the security part, WhatsApp also included the much neglected Two-Step verification functionality.