WhatsApp is rolling out a new update with version number 2.19.20 for iOS which brings new features such as call waiting, redesigned chat screen, and more. On the other hand, the beta version for Android (v2.19.348) adds Snapchat-esque disappearing (self-destructing) messages.
WhatsApp adds a new call waiting feature to the app similar to what we have for normal calls on phones. Which means when a user is on a call, they will receive a notification if they receive another call.
The latest WhatsApp stable update for iOS also brings a new privacy feature which allows users to control who can add them to groups. This functionality can be accessed from Settings -> Account -> Privacy -> Groups.