Some weeks ago Whatsapp released an upgrade where whatsapp users can delete a message from both end with 7 minutes of the message been sent.
Recently Whatsapp beta demo was released with two new and special features.
You can automatically switch from Voice call to Video call but will need the approval of the other user.
A screenshot was given in one of their tweetWhile recording a voice message you can just you can just click on a new toggle which will appear and this will make your recorded messaged locked.
These new feature are now in the new Whatsapp beta app which is onPlay store
Note: you can be a tester of this amazing app, before the official version is released.