Facebook has been accessible through Tor-enabled browsers since 2014, but starting today the social network is making another step in protecting your privacy. That's because the Facebook app for Android supports Tor now too. To use the app through Tor, you first need to install the Orbot proxy app on your device. After you do that, if you go to Settings inside the Facebook app, you'll see the option highlighted in the screenshot below. Turn that on, and you'll be connected to Facebook via Tor. The feature will apparently be rolling out over the next few days to users of Facebook's Android app, so you may not see it...
Source: http://www.gsmarena.com/facebooks_android_app_now_has_tor_support_builtin-news-16173.php
