Popular apps coded in Python

Hi smart peeps!

I am looking to create an app with my brother. We both know python very well, and don't have the time/desire to learn another language or stack like React Native.

I've heard python isn't great for mobile app dev, but big apps like Reddit and LinkedIn are coded strictly in python (to my knowledge). I can't seem to find what framework they are using. I doubt Kivy. Doesn't anyone know?

Thank you for your time! I really appreciate it 🙂