Apple made the official announcement of its App Store’s 25bn downloads milestone yesterday. The 25 billionth was the free version of Disney’s game Where’s My Water, and it was downloaded by a Chinese iOS users called Chunli Fu, who gets a $10k iTunes gift certificate as a reward. In its announcement, Apple reiterates that it has sold more than 315m iOS devices since the launch of the first iPhone – the figure includes iPhone, iPod touch and iPad sales. That means we can do some quick number crunching. The average iOS device has downloaded just under 80 apps from the App Store. Meanwhile, the 550,000 apps on the store have done an average of just over 45,000 downloads each.