Cool Java projects I can work on? OOP related

Question

I'm looking to make a few java apps to practice and learn, I'd say my proficiency is intermediate and I want to practice building apps in Netbeans (along with GUI interfaces). Does anyone have some ideas of projects I can work on (i.e. What app / functionality I should build), something that has an emphasis on using objects. Much appreciated.

Answer 1

For example, I recently made a GUI calculator which was fun, but didn't create new objects during execution and was more "event driven"

Answer 2

If you're intermediate I would suggest work on Java along with a SQL database, regards