Apps for an LG phone are not the same as apps for an iPhone, but many apps have both an iPhone version and a version compatible with the Android operating system used by LG phones. Android and iPhone versions of apps are usually similar, but performance and functions may differ.
Almost all modern LG phones as of 2015 use the Android operating system, a modified version of Linux created by Google for cellular phone and tablet use. Android is different from the Apple iOS operating system used on iPhones and iPads, so programs written for one type of phone are not compatible with the other. However, makers of many popular applications, such as games and video streaming services, write versions of their apps for both iOS and Android devices. There are some notable exceptions for apps that use proprietary features of one operating system or the other, most notably Apple's iTunes.
The iPhone version of an app is usually very similar to the version available on an Android phone, though there are frequently differences that depend on the special features of each operating system. For example, iPhone apps access the Apple App Store for updates, while Android apps typically update through the Google Play store. There may also be performance differences between the apps, especially if the LG phone on which the Android version of the app is installed is more or less powerful than the iPhone that the iOS version targets.