Facebook is supporting Tor users for past few months for people who are been concerned about keeping your social network activity private, but not on smartphones.
Today Facebook introducing Tor support on Android device, using Tor app you can encrypt your Facebook viewing.
Download and install Orbot proxy app for Android device. After installation, open Facebook app and click “App Settings” menu to enable the feature using a new preference switch. For more information visit Tor Project’s Android page and Facebook over Tor.