I currently have an iPhone 7 that I use to test and send my apps to the store, but I know that I won't be able to continue with iOS 15 for a long time due to the updates required by Apple, I'm on xcode 15.1 and sonoma 14.2.
My question is, can I get a good lifespan with an iPhone 12?
Another question, is it really mandatory for me to have a physical device to launch applications in the store?