JoinFinder is a useful tool that helps you to find join between two tables by foreign keys defined into tables or by a brute-force method.
It is a Java8 project and it uses jna library for autocompletition feature.
At the moment JoinFinder is in Italian and supports only MS SQL server, but I hope to add soon other DB support and English translation.
...It is a collection of PL/SQL packages and related tables, which provide a starter framework for custom PL/SQL-based applications. Save months of design/build time. Includes logging, debugging, timing, locks, common messages, file reading/writing/management, email from within the DB, user/role security, and more.