Most iOS apps don't get any downloads and are nearly impossible to find.
The company is demanding more evidence in its trademark battle with Amazon.
Free apps now make three times as much as they did in 2010.
"Free" is pretty common, but it's not the most popular.
Developers have earned $5.5 billion from the store.
The company promises to fix the problem permanently in iOS 6.
Apple's platform continues to be very lucrative for developers.
An insider offers advice for getting attention from Apple.