No one can deny that using an iOS device comes with restrictions. A user can only download programs from the App Store, and App Store apps have very limited control over the device. This is where profiles come in.
What are Profiles?
Simply put, a configuration profile is an XML profile that can change device settings. Their goal is to allow developers to provide custom settings for a large amount of devices. They can be installed through Mobile Safari, email, or with Apple Configurator. Some common uses for profiles are requiring a password, disabling certain features, and creating web apps.
The GBA4iOS method
GBA4iOS is an emulator for iOS. It allows iOS users to install a full Game Boy Advanced emulator on their device, without jailbreaking. The website accomplishes this by installing a profile, specifically the MacBuildServer(MBS) Hello App Provision. This profile allows other applications to be installed on the device. Other applications can be found at iEmulators. This provides a screen recorder, other game emulators, and even a full DOS emulator. With iDOS and the help of iExplorer, you can even install Windows on your device.
Testflight and Hockey
Testflight and Hockey are both systems for developers to let testers download their apps. They also use provision profiles to download apps that don't reside on the App Store. Both make testing easy by simply providing a profile to download. As soon as apps are available, testers can download the apps straight to their device. This allows developers to test in a wider range of users, not just personal connections.
GBA4iOS, Testflight and Hockey provide iOS users a way to download apps that don't come from the App Store, without jailbreaking. More options are being worked on, as developers push the limits, finding other ways.
Do you use these? Or any other methods?