In order to facilitate the refund period and fight piracy, we use Google's licensing server to validate your license online in the first 24 hours after purchasing the app. Please make sure you are online in the first day or two of use, after that there will be no more license checks, unless you re-install the app or clear its cache.
The checks will occur at first start-up and the first time you start up the app after 24 hours of purchase.
This licensing scheme is in effect from version 3.0 onwards. If you purchased the app prior to the release of version 3.0, your license will be checked once more after 90 days of your purchase, and not anymore after that.
There are several things to try when you see the license validation failure message. Here are the most important ones:
If all this fails, please contact us at email@example.com, stating your Android model, Android version and the GMail account that is currently active in your Play Store app.