How to automatically update an iPhone app from within the app itself?

Question

This link shows a video where an app upgrade is "forced" from within the app itself:

http://buzzworks.de/blog/update-ios-beta-apps-from-within-the-app

The App Store is not called in and it's said to work only for AdHoc apps.

Anyone knows how is this possible?

edit: please give a look to the video before answering. AdHoc apps are signed by the developer and they do not come from the App Store. This sort of forced update is useful when doing beta testing and in enterprise applications.

Answer 1

I've found that it's all explained here:

http://developer.apple.com/iphone/library/featuredarticles/FA_Wireless_Enterprise_App_Distribution/Introduction/Introduction.html

The developer should create an .ipa with the app and a manifest in plist format with the URL to the .ipa and a few other things.

The app can optionally implement its own way to find if an update is available and open the URL to the manifest.