It has come to our attention that customers have asked several times about issue regarding application license.
Google Play License is integrated to protect our applications from pirates.Licensing Overview
Google Play Licensing is a network-based service that lets an application query a trusted Google Play licensing server to determine whether the application is licensed to the current device user. The licensing service is based on the capability of the Google Play licensing server to determine whether a given user is licensed to use a given application. Google Play considers a user to be licensed if the user is a recorded purchaser of the application.
The request starts when your application makes a request to a service hosted by the Google Play client application. The Google Play application then sends a request to the licensing server and receives the result. The Google Play application sends the result to your application, which can allow or disallow further use of the application as needed.
To properly identify the user and determine the license status, the licensing server requires information about the application and user--your application and the Google Play client work together to assemble the information and the Google Play client passes it to the server.
When you open your application first time the application initiates a license check through the License Verification Library and the Google Play client, which handles communication with the Google Play server.
The license will be cached in your device for 3 months, after expire date it will extended automatically again for 3 month, on the time when you open your application (your device has to be online, to extend automatically license and so on).
If for some reason you have a problem with license, please follow the next steps :
1. Delete application
2. Go to Settings->Apps
3. Find Google Play services->Storage and clear Data and Cache
4. Find Google Play Store->Storage and clear Data and Cache
5. Open Play store, login and install application.
If you still have any issue or question please ask via e-mail info[at]marineapps.co.uk
Thanks and good luck!