Hey @ChrisBeach and @robmc,
I have an update on this: a few days ago, finally, a standalone app for a Discourse site I have worked on was approved by Apple. You can find it in both app stores (iOS/Android) under the name Swapd.
So, this app is NOT using the same code as the official Discourse app. It’s inspired by it, but it’s a separate app. There is some work to be done per app to maintain, but I do have a common codebase that I am planning to use for multiple Discourse sites.
I will post the common codebase soon, once it’s cleaned up. And I am also available for improvements and bug fixes on it, so if you’re interested in a branded app, please get in touch.