Really sweet project! I agree that even if not that many people may use it immediately, it’s cool that you could verify that within a couple of hours thanks to Expo.
I did a similar project and wrote about it in an earlier blog. One challenge I faced was getting through Apple’s approval process, specifically this one:
Your app should include features, content, and UI that elevate it beyond a repackaged website. If your app is not particularly useful, unique, or “app-like,” it doesn’t belong on the App Store. If your App doesn't provide some sort of lasting entertainment value, or is just plain creepy, it may not be accepted. Apps that are simply a song or movie should be submitted to the iTunes Store. Apps that are simply a book or game guide should be submitted to the iBooks Store.
I’m not sure what exactly passes as “app-like” to Apple. Mine was only opening links in the browser and sometimes in Reddit, or Youtube but it may be different for music apps.