I just installed an app from a website - with no profile, no UDID, no anything. It just started installing. How is this possible? I am not jailbroken, not running the new beta 6. When it finished installing I tapped on it and it asked me if I was sure I wanted to run this app.
They seem to have an Enterprise Developer Account that allows over the air distribution to any iPad without the need to add each device's UDID.
The process to provide such an app is similar to providing an AdHoc Distribution with your "normal" Developer Account. You build your app for distribution and upload the .ipa bundle and a manifest .plist file to your server. Then you can use a link like this to make the app downloadable to users:
<a href="itms-services://?action=download-manifest&url=http://example.com/manifest.plist">Install App</a>
The only difference with an Enterprise Developer Account is, that you do not have to provide the UDID for each device you want to use. The link works with any device.
来源：https://stackoverflow.com/questions/11741111/install-ios-app-directly-from-website-no-password-no-itunes-no-udid