SQuirreL SQL Client is an open-source Java application that allows working with databases via JDBC. You can download Squirrel SQL here: http://squirrel-sql.sourceforge.net.
Start Squirrel SQL and go to Drivers. Right-click HSQLDB Server in the drivers list, and choose Modify Driver.
Go to the Extra Class Path tab in the window that appears, and click the button to add the .jar file with the driver.
Then you need to select the hsqldb-x.x.x.jar, driver, which you should download from HSQLDB website in advance. If you are using HyperSQL only for CUBA development, then you can add the driver supplied as part of CUBA Studio (it is located in the lib subfolder).
Next, create the alias for connection to the application database.
Fill in the connection properties in the window that appears: Database URL, username and password. The default user name
is "sa", the password is empty. The database URL can be copied from the Project properties tab in CUBA Studio, or from the modules/core/web/META-INF/context.xml file of the project.
