i have purchased a APP from the app store in itunes, it s air nav pro and was downloaded on the the ipad. now i tried to log in in the mac app store and searched for the app but it does not recognize my purchaes ! any ideas? i dont want to buy it again !

The apps in the iTunes App Store are for iOS devices, iPhones, iPads, etc. The apps in the Mac App Store are for Macs. Apps for iOS devices do not run on Macs. Apps for Macs do not run on iOS devices. Your purchases in the iTunes App Store will never show up in the Purchases pane of the Mac App Store. They are two different versions of apps for two different operating systems. If a developer has developed a version for both platforms they must be purchased separately.