App screening process

What is Apple's screening process for Apps? I bought the Lexulous app for $4 and it constantly crashes. I have reported it 3 times to the creators with no solution. If you read the reviews, there are hundreds complaining of this problem. They did an update, but the problem persists. I feel that they should be held accountable for selling a product that is almost unusable. Apple should at least tell them to either fix it or drop the price to "free". Any ideas on how to solve this problem. Does Apple care what apps are being sold in their itunes store?