Windows may surprise you by showing next dialog when running downloaded app.
Windows sees sign of app to think it is worth telling you the risk. Query Viewer is signed with self-signed-certificate by Kappa Project, and installing certificate in your PC may reduce chance of seeing that annoying dialog, but unfortunately you still see that in some cases.
Download and install
Download this ZIP file to any folder you like and unzip. Double click "kappa.cer" file.
Click "Open" button.
Click "Local Machine" and then "Next" button.
Click "Install Certificate..." button.
Select "Place all certificates in the following store" and click "Browse" button.
Select "Trusted Root Certification Authorities" and click "OK" button.
Click "Next" button.
Click "Finish" button. Now certificate was installed in your PC.
You can delete downloaded and unzipped files.