Right now, Facebook Live is exclusive to iOS devices with the Facebook app in 30 countries around the world, but it used to be even more exclusive than that - only celebrities and verified accounts could previously use Live starting last August.
To start a Facebook Live video, you just open the Facebook app and tap on "What's on your mind?" at the top of the News Feed and tap the Live Video icon. You can write a description and choose your audience before going live, and during the broadcast you can see how many people are tuning in, the names of those people, and a stream of real-time comments you can respond to. It's very similar to Twitter's live streaming app Periscope.
In its blog post, Facebook said it's seeing people watch live videos for more than three times longer than videos that aren't live. And it said more than 50% of people watching live videos are watching them off Android devices - hence the move to bring Facebook Live to Android.
Facebook has been making a big push into videos over the last year or so. The company has been working hard to design a system that encourages video uploading and distribution, and it's been paying off. The company had about a billion daily video views in September 2014, then 4 billion daily video views in April 2015, and then 8 billion daily video views in November of that year. Facebook introduced auto-playing videos in December 2013, and the company continues to experiment with new features to get more people to watch videos on its platform.