CheckoutApp's crack that was released just resets the demo time period. Every 30 days you will have to overwrite a file to get access back to your store.
http://www.mac-bb.org (a really cool warez forum) has the application as well as the crack...little work for you to do here
This time reset is done with 1 file called: com.madebysofa.Checkout.plist
you have to replace it over at ~YOUR HOME/Library/Preferences
so far, you will be able to login to your store but you will see the count of days left reset to 30 days.
So to override this you replace English.lproj folder over at checkoutApp...to do so, go to your Applications folder, right click on Checkout and click "Show Package Contents" and replace the English.lproj in Contents/Resources/English.lproj
now, you will see that the copy of checkoutApp is licensed.
