If you wait long enough.... eventually most apps go "free" or at least on sale. But often times there is a time limit, sometimes only an hour! So when you see it's free, you have to get it!
So far I have found 2 places that recommend great free apps throughout the day. One updates to my facebook account, the other comes as an email. I have probably saved hundreds of dollars from these to sites alone!
What are they you ask?