Due to increased competition, Apple's iPhone is less synonymous with the term "smartphone" than it was in earlier years. While the iPhone is being challenged by other brands, such as Android and Samsung, it's still the go-to phone for many users. The iPhone offers a sleek design, is user friendly, features fast browsing speeds and is currently available from all the major U.S. cell service providers. There are several other features and advantages that make iPhone a must-have among user