The system requirements says Norton for iOS will support current and 2 most recent versions of iOS. Is that major or minor versions? For example, when iOS16 is release are 14 & 15 supported? Or just 15.5 and 15.6?
You are welcome. Glad I could help.
Very helpful...thank you!
If you open the Apple App store app and search for Norton 360, then tap on it and scroll down to the Information section, you will see a compatibility section. It defaults to letting you know if the app is compatible with your device. If you tap on that it will show you what the minimum required OS version is. Currently is shows version 13.0 or later.
@peterweb
Thank you for the reply/info. Are you aware of documentation from Norton to support this? Or is your answer based on general knowledge / experience?
I hope to keep my phone (iPhone SE 1) past this year when Apple no longer provides updates. I realize there are risks for that, but am considering adding N360 to my phone to minimize that risk. But if support from N360 runs out after minor releases, my idea won't work.
(Just one of those guys who resents having to buy a new phone when mine works perfectly fine. 
Hey, you don't have to replace your toaster every 5 years! 
)
Your first example is correct. It the the Major version that is counted.
As long as you do not uninstall on an older device, you will still be able to use that product until you uninstall for any reason. ie If you are currently on iOS 13.X and 16 is released, you can still use your installed version of 360. But I do not believe you will get any product updates.