I also had awesome results from asking for reviews using appirater. I have mine set for 20 days and 20 uses. (They will not be asked to review until they have been using it for at least 20 days and have used the app at least 20 times)

I now have over 50 reviews for the current version with a 4-5 star average.

http://itunes.apple.com/ee/app/icross-wod-free/id397702723?m...