Very powerful

For building my own product and client database, I looked into several plugins. In the end, WP Data Access offered exactly everything I needed in one package (data table builder, form builder, REST API, PDF export, customized themes) for a very affordable price, with the possibility of a lifetime license payment. The documentation is not completely up to date, and sometimes not very explanatory, but that can be solved by reading up on SQL. Highly recommended, also for database amateurs like me!