They are already already available. What are you asking? Either Rigelian or Soundirok are my preferences. Each has strengths and weaknesses. Either is significantly better than MM for music listening for my style of listening. Of course a web interface is great for settings and firmware updates, ...
If you are asking if Bryston should make an app like Rigelian, i would answer yes. It is an app for many devices. You could optimize your Bryston app to be killer for Bryston stuff only. Also you could control the continued development of the app.
I know it is a pain to create apps for the apple store. They have a lot of conditions and approval steps. But I think your products deserve and need a dedicated Bryston app.
I don’t think that Bryston should develop an app of its own. Berrie and Bryston have been working together already and Rigelian is very promising. It could take a lot of time for Bryston to finish the development of Nutty Narwhal and a companion app.
My first streamer had a GUI and an app, which was a version of iPeng with some cosmetic changes. The developer of iPeng was far more active with updates and upgrades so after a few years, the adapted version was removed from the Apple Store, in line with Apple’s policy.
As I use an iPhone it doesn‘t concern me, but is there a comparable app for Android? Aurender, for example, offers a very good app for iPad only but leaves Android users in the cold. There should be apps for the Bryston for both camps, in an ideal world the same apps. Berrie has announced there will be no Rigelian for Android. Could he change his mind?