The JCR queries app allows you to run JCR queries. The tool is a good place to test queries. You can write the queries in SQL-2, SQL and XPath and run them on any workspace. The app is accessible in Dev > JCR queries.
The JCR queries app is a 4.5 legacy app installed by the UI AdminCentral module. The Dev app group that this app belongs to is only available to the
superuser role. This is configured in the app launcher layout. The app is configured at Configuration >