Definitely you will need to have patience to find ones that catch your fancy. Also no one job going to give you idea, but when you read a lot of them, you start to see patterns and might develop linkage that will make interest project for you.
"He has an entire team of people who read reviews on Amazon, looking for moments when people say, "I wish this speaker were rechargeable." Pikarski then makes a rechargeable version. "
http://www.fastcompany.com/3021229/chaim-pikarski-the-amazon...
I did spend one Sunday afternoon reading up reviews on apple app store. while there were some pretty interesting ideas, I saw one huge issue - the search on app store is unreliable. One, there could be an app implementing the said "idea" or "feature" but somehow not readily visible. Second, no way to really dig and learn about your competitors. Third, the same search might hurt the app chances.
Here is a blogpost I wrote about them. http://www.davidmelamed.com/2013/11/22/what-customers-really...
Here is a Fast Company feature about them http://www.fastcompany.com/3021229/chaim-pikarski-the-amazon...