San Francisco, Nov 2 : Facebook after rolling out the 'Dark Mode' for billions of users on Android smartphones has finally started the same on the iOS devices. Evidence that Facebook had been working on a 'Dark Mode' for its official iOS app first surfaced in April and by June a small percentage of users had access to the setting hinting that the company was gradually rolling out the feature for testing purposes, reported MacRumors. To see if 'Dark Mode' is available through Facebook account on iOS, first make sure you have the latest version of the Facebook app from the App store. Then open the Facebook app and tap the three lines at the bottom-right of the navigation bar. Finally tap "Settings and Privacy", look for a new 'Dark Mode' option and choose between "On, Off or System". Instagram, WhatsApp and even Messenger have already gained 'Dark Mode' support built into the app. 'Dark Mode' helps users enjoy lower brightness with contrast and vibrancy, thus minimising screen glare for use in low light. /IANS