During a call with investors today, Facebook CEO Mark Zuckerberg announced that the social network had reached over one billion mobile users. That’s up from only 945 million active users in the last quarter of last year, putting the total gain since then at about 55 million mobile users.

The Facebook-owned photo app Instagram also announced a milestone today on its blog as it passed the 200 million user mark. A quarter of those users joined in just the last six months. Instagram also announced that users have shared over 20 billion photos on the network since it launched.