Teaching a free Python course at local charity. Need help with idea.

Hello!

I'm teaching Python from scratch at local charity this September.
I'll use existing lessons from other Python courses I've done in the past.

I need your help with the starting project.
In my other courses I usually do a mix of text editor, flashcards, note taking, to-do list, calculator, dice rolling, quiz game, etc.
Those have worked in the past and will do the job, but are kinda lame.
I'll will still go trough some of those as there are lessons there.

Looking for something that will capture attention at start.
Trying to create a "Aha!" moment for the students.

Is there a perfect starter app that can be built up from a small start?

Thank you for any answers!