Hi. Thanks for giving it a try. If you are happy using the Pi MusicBox web app in a browser, you definitely don't need this app. And if it is more responsive than Firefox, the only reason for that would be that the Chrome-based web view I am using is more responsive than Firefox.
I took the trouble to write it because my Pi-based network radio has gotten good enough that I use it almost every day, and I want that experience to be streamlined. Pi Music does that in a lot of little technical ways that are best experienced by just trying it.
But, being happy with the web app in a browser is not a response that I would argue with! I wrote Pi Music because I discovered that the web app was more useful than the native MPD clients for Android, and I wanted it to be a little easier to use.