If your iPhone is compatible with iOS 14, it supports iOS 15. This includes the iPhone 6S Plus and every iPhone model released after that through iPhone 13, 13 Pro, and 13 Pro Max.
Google Maps is the most widely used map app in the U.S., but iPhone users have to use Apple Maps by default. If you’d rather use Google Maps as the default map app on your iPhone, here is what you need to do.