Create an app with code from GitHub?

Hey guys, I want to create an app that also serves as a website. I've found something for the website that takes my files from GitHub and hosts them as a website. Now I wanted to ask if there's a website that does this for an app. The most important thing would be that if I change something in the code on GitHub, it's also changed in the app. This is supposed to be a small streaming app/website for me and my friends.

Thank you in advance

I hope for a quick and helpful answer