Did you just find a file that has a digital signature from GT Booster Inc.? If that's the case, please read on.
You will probably see GT Booster Inc. when clicking to run the file. The publisher name is then displayed as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view the additional details from the GT Booster Inc. digital signature with the following procedure:
Here's a screenshot of a file that has been signed by GT Booster Inc.:

As you can see in the screengrab above, the Windows OS reports that "This digital signature is OK". This implies that the file has been published by GT Booster Inc. and that no one has tampered with the file.
If you click the View Certificate button shown in the screenshot above, you can view all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, and so on. You can also view the address for GT Booster Inc., such as the street name, city and country.
DigiCert Trusted G4 Code Signing RSA4096 SHA384 2021 CA1 has issued the GT Booster Inc. certificates. You can also examine the details of the issuer by clicking the View Certificate button shown in the screencap above.
The following are the GT Booster Inc. files I've gathered, thanks to the FreeFixer users.Unfortunately I don't have any scan result from VirusTotal available for the GT Booster Inc. files at the moment. The scan results will appear here as soon as a FreeFixer user uploads a file digitally signed by GT Booster Inc..
| Detection Ratio | File Name | 
|---|---|
| Not available | GameTurbo.exe | 
The analysis is based on certificates with the following serial numbers: