Apple CEO Tim Cook said that the company has paid out around $8 billion to developers. This is about a $1 billion increase since the last time the numbers were announced on January 7th. In October 2012, Apple said that they paid $6.5 billion to developers in October.
Consumers have a tendency to spend more on apps during the holiday season, which explains the $1 billion increase in about a month.
The Apple App Store hit around 775,000 app mark in December and there are over 300,000 apps designed for the iPad.