Challenges to keep on practicing

New to bubble but progressing more than I expected. I finished a bootcamp and started doing micro-challenges to practice my building skills. I want to know what small applications come to mind for keeping on practicing that are progressively more complex and add new functionalities as they grow in complexity.

some of the ones I made are:

simple calculators, search tools, login/signup flows with privacy laws for each user, etc

thanks so much for your help

Start making your own app based on your idea and most important FINISH IT you will learn all of it!

i fear i still dont know that much for what i want to build yet