To me, a learning needs some kind of gamification and engagement tricks. There is nothing calm about learning, you need the dopamine! Among other things, dopamine is the learning hormone, it is a problem when it makes you learn the wrong things, like "fentanyl is really great", or "I need to buy more stuff I don't need", but it is also what helps you learn useful skills and life lessons.
I remember my father, a teacher, who told me he viewed his job in the classroom as a performance art. His knowledge was secondary, if that's knowledge you want, just read a book, go to the internet, whatever, you don't need a teacher. But it is not very engaging, and a teacher's job is to make it more engaging.
So without engagement, you probably won't make a good learning app, but you can make the engagement entirely targeted towards learning and not monetization, which would be a very good thing.