Updates to any Google Play app can be automatic or manual, but it takes a few days from when they are published on Google Play until the app is updated on your device.
Therefore, thanks to Update for WhatsApp you will be able to receive notifications of new WhatsApp updates, and have the new version installed in seconds and without waiting. You will be able to access new features or functionalities before anyone else, and you will be able to have those errors or bugs of the most popular chat app resolved.
This app is NOT affiliated with WhatsApp.
WhatsApp is a registered Trademark of WhatsApp Inc.