WhatsApp is working to add fingerprint authentication to its Android client, as discovered in recent preview versions of the application.
WABetaInfo writes that while the Authentication feature is not available in beta build 2.19.3, it is something that the WhatsApp development team is working on, with the goal of making it available for users at some point in the near future.
Basically, this feature would allow Android users to lock access to WhatsApp using the fingerprint sensor on their device, provided there is one. As a result, WhatsApp would require authentication every time when launching.
If the fingerprint can’t be used for unlocking WhatsApp, users can turn to alternative authentication methods, like entering the backup PIN configured when setting up fingerprint scanning on their devices.
Feature also being tested on iOS