Say what you will about Facebook's commitment to privacy, the company does offer a Tor address for secure, anonymous connections. That's cool, but you need to use a Tor-enabled browser. That will change in the coming days as Facebook rolls out support for Tor in the Android app.
Tor is an encrypted network that can route your traffic through multiple layers to hide its origin. It's useful for bypassing website blocks and preserving your privacy. Oh, and also for buying drugs and whatnot via hidden Tor services, but that's neither here nor there. Facebook launched a Tor .onion address in 2014, and now the Android app will get built-in support to connect via Tor. It shouldn't require a lot of setup either.
To make this happen, you'll need to install the Orbot Tor proxy app, which is in the Play Store and also on F-Droid. Once you connect with Orbot, you can flip the switch in Facebook, and it will route the connection over Tor. It's not clear if this option will be added in an update (in which case we'll let you know when we have the APK) or if it's a server side switch.