Photo app Instagram and Rovios Angry Birds Space have both passed 50m users.
Instagram, which was acquired by Facebook last month for $1bn, has been growing at a weekly rate of 5m users a week over the last fortnight. It started the year with 15m users on its iOS-only app, but has since added an Android app – which, along with the attention it has received since the acquisition, probably helps account for the explosion in users. 
Angry Birds Space, meanwhile, has added 7m a week. Its taken 35 days for the game to hit the 50m download milestone, making it, according to Rovio, the fastest growing mobile game ever.
