Yes, you can also use the headphones without the app. The app is mainly needed for adjusting the noise cancellation (ANC) and other personalised functions. Without the app, the headphones continue to function as normal in-ear headphones with a wired connection via Lightning. However, the app offers additional functions such as user-defined equaliser profiles and HearThru technology, which makes ambient noise perceptible.
As far as I know, the headphones are not compatible with the iPhone 15, as the connection has changed to USB C from iPhone 14. I still had the headphones with IPhone 12 at the time
Hello Schweigefux, I bought the headphones this week and experimented a bit with the equalisers in the Rayz app and Spotify. Both are independently configurable and also boost/weaken each other. What I can't do, however, is configure the smart button to open Spotify at the touch of a button. I hope that this will be added soon with a software update. I hope I was able to answer your question satisfactorily.