Unfortunately Chess Openings Trainer is not available on the Google Play Store anymore. This can cause licensing problems with the google licensing server. To resolve this issue a new Chess Openings Trainer Pro APK is provided (download link provided at bottom of this page). The new APK must be unlocked with an activation key to get access to full functionality. The activation key will be sent to you by email after providing a proof of purchase. After installing the APK, you will be able to enter your proof of purchase directly in the app.

​

Notes:
If you have a backup file of your openings, you will be able to use the restore function to recover your work. If you have never created a backup file, before uninstalling, you can try creating a backup file by clicking the Backup button before the license dialog box opens. Some users have been able to create a backup by turning off their mobile data before opening the app. This gives some time to click the Backup button before the license dialog box appears...

​

Step by step procedure for installation of the APK:

 

1) To avoid conflicts with the old app, uninstall the current version of the "Chess Openings Trainer Pro" app.
Anyway, this old version can no longer be used, because the Google license server is down for the application.

 

2) Install the new "Chess Opening Trainer Pro" APK.
Download the APK and install it using the provided link (at bottom of this page). You may receive a warning that the file is too large to scan by google, just ignore it and go ahead with download. Depending on your device, you may be able to install the APK using the suggested installer, if so click on it.

​

Note:

You'll need to change your Android settings to allow the installation of APKs from "unknown sources" (enable the option). Once enabled, go back and click "Install." Google Play Protect provides an extra layer of security by automatically scanning apps, including those installed from outside the Play Store. Accept the scan and install the app.

​

3) Once the new app is installed, open the app.
Some features of the app will be "locked":
- restore a backup file will not be possible
- create more than 3 openings will not be possible
- export a PGN file will not be possible
- importing a PGN will also be limited to only 8 moves
- etc...

​

4) To unlock all the features of the application, you will need to request an activation key directly in the new app. From the main menu, click on the key button and enter the proof of purchase information (transaction ID and date). Send the email without any modification and you will receive a reply with an activation key within 48 hours. If you haven't receive it make sure to check your spam folder.

​​

Note:
In the next section, you will find a procedure to find your transaction ID and transaction date.
Emails containing a fraudulent or invalid transaction ID will be ignored.

​

5) Once you get a reply by email:
Copy the activation key to your clipboard. Click the red lock button in the main menu of the application and paste the activation key there. Make sure to paste the entire activation key string without adding any extra spaces at the end. If activation is successful, the lock button will turn green with full functionality.

​

Notes:
The activation key is only valid for your specific device, it will not work for other devices. If you uninstall and reinstall the app, you will need to enter the same activation key again, so keep this key safe. If you clear the app storage and cache, you will also need to enter the same activation key again.

 

Step by step procedure to find your GPA transaction ID (GPA.xxxx-xxxx-xxxx-xxxxx):

 

Method #1:

If you still have the purchase confirmation email that was sent by "googleplay", the transaction ID (GPA.xxxx-xxxx-xxxx-xxxxx) and date will appear at the top of that email.

​

Method#2:
If you cannot find the email, you will need to download your activity data from Google Play Store, which will include the order history of all the apps you have purchased.

​

1) Make sure you are logged in with the same user account that you used to purchase the app.

 

2) Open the "Google Takeout" service by clicking on the following link:
https://takeout.google.com/

Note:

Login with the same user account that was used to purchase the app.

 

3) You will see the list of all Google products with checkboxes on the right.
Click "Deselect all" at the top of the list, no products should be selected.
Scroll down until you find the "Google Play Store" product, make sure not to select "Google Store" which is different from "Google Play Store".

 

Note:

The icon of the "Google Play Store" product looks like a colored "play" button.

Click on the checkbox on the right associated with "Google Play Store" in order to select this product.
Scroll down to the bottom of the page and click "Next step".
Leave the destination as "Email download link" and click "Create export" at the bottom of the page.