Stupid question— joining arena doesn’t let me use the native app?

Stupid question- when I join the arena through the native app, it brings up the browser-based game. Is there a way to use the native app? 

idk what you're talking about

Using the iOS app, when I join the GM Factory arena and start playing, the chess game is the browser-based version of the app, it does not re-direct to use the iOS version. Does that make sense?

Yeah, you cant join arenas in the app and you cant play spell chess for example as well. The only way to do either of those is to play within your mobile browser.