WhatsApp, the messaging service app that recently introduced voice calling for Android and iOS users, is now offering Facebook integration as well. Android users can follow the instructions below to start using it.

Facebook acquired WhatsApp last year for $19 billion, and now the benefits of that acquisition are beginning to show, as the companies have quietly introduced what looks to be the beginning of an integration of the two services.

Beta users of the Facebook Android app can now share messages and news items with their WhatsApp contacts via a dedicated "send" button appearing on a newly introduced version of the app. The button is at the extreme right-hand side after the usual "like", "comment" and "share" buttons.

This looks to be the first of a further integration of Facebook and the newly acquired messaging service. But as Facebook still has its own messaging service, Facebook Messenger, up and running as well, and in many ways competing with WhatsApp, it remains to be seen what additional synergies will be created. So far, WhatsApp's CEO Jan Koum has stated that the company will continue to function independently despite the Facebook acquisition.

So how can you get in on the integration now? All you need to do is sign up to be a beta tester for Facebook's Android app. The instructions can be found here, but basically involve joining the appropriate Google group for Facebook Android beta testers, and then downloading the app from the Google Play Store. Your version of the Facebook app should then be the one that contains the "send" button which allows you to share news and information with your WhatsApp contacts via the service.

If you prefer to wait for the feature to be officially added to the Facebook Android app, no time frame has been announced. It is likely that the feature will also be offered for iOS as well sometime in the future.