It is very common that OEMs include some preinstalled apps when you purchase a phone, some of them could improve some aspects of the operating system while most others will end up never being used because what they do would seem repetitive or in some cases that app is simply just not needed. Of course, there are also native apps included directly by the company responsible of creating the OS, they usually perform the most basic functions like dialing a number or saving some contacts into the phone, as these devices became more powerful, more apps were included such as a browser, music player, image and video viewer, etc. They usually go along very well with the OS since they were designed specifically with that system in mind.
Apple's WWDC15 event was held today, it's the annual event of conferences dedicated to developers so that they can know the new technologies and innovations that will be integrated with the operating systems from that company. In this event, the company announced their newest mobile operating system, iOS 9 and the improvements it would bring compared to the last version and at the very end, they announced a streaming music service called Apple Music which will have to compete with services like Spotify, Google Play Music or Rdio, so an app for Android is expected to be released this fall, becoming the first app from the company to be available for Google's OS.
While it wasn't announced at the conference, the page for the preview of iOS 9 suggests that another app will be available for Android, this time to help users transfer their information to a new iPhone. It will apparently be called "Move to iOS" and the transfer will happen wirelessly, which is an interesting move from the company to try to convert some Android users into their ecosystem, far more aggressive than the tutorial published in their site. The app will copy the user's contacts, messages, web bookmarks, e-mail account information and files like images or videos, songs and books. As for the apps stored in the device, it will try to find the ones that are free on the App Store and make them ready for their download, the paid apps will be kept in the Wish List so that the user can download them later. The app has not been found yet, so it will probably launch along iOS 9 in the fall.