As an Android, linux, and Windows user...I've been having the most outrageous time getting anything to work as expected with my girlfriend's iPhones. Issues, up

As an Android, linux, and Windows user...I've been having the most outrageous time getting anything to work as expected with my girlfriend's iPhones. Issues, upon issues, upon issues of how services or software is expected to work...yet never having desired results. A few days ago, I held her iPhone 6 for the first time since she got it a month or two ago. I felt like I was holding the greatest piece of mobile technology in existence, except I knew it ran iOS and only iOS.