Using 'iPhone', 'iOS', 'Siri', or Apple's logo in your app name, icon, or marketing materials without following Apple's trademark guidelines is a quick rejection. Here's what's actually allowed.
What Apple said
“Your app name, icon, or metadata includes Apple trademarks (including 'iPhone,' 'iPad,' 'iOS,' 'Siri,' or the Apple logo) in a manner that is not consistent with Apple's trademark guidelines. Please review the Apple Trademark List and update your app accordingly.”
Apple is extremely protective of its trademarks. You can't use 'iPhone', 'iOS', or the Apple logo in your app's name or icon. You can mention that your app 'works with iPhone' in descriptive text, but that phrasing has to follow Apple's exact guidelines. Using 'Siri' as a character name, or making your icon look like the Apple logo, will get rejected every time.
While you're at it — Apple also requires these pages for every app.
Fix this rejection, then make sure you're covered on the compliance side too. Apple requires every app to link to a hosted Privacy Policy, Terms of Service, Support page, and Data Deletion page. No link means another rejection — just for a different reason.