Automatic Authentication on iOS
The full-size icon is just a 512x512px png file, but things get exciting when you know that the png specification does declare ancillary chunks, including one to store text. This means that HockeyApp can pass textual information into your build at installation time without modifying the .ipa file.
Coming back to the user that taps the Install button: If the user is signed in or his UDID is present in the current browser session, then HockeyApp writes this information into the metadata of the full-size image. The new version of HockeySDK parses this metadata at the first start to automatically identify the user. Thereby the SDK utilizes the same URL scheme that we introduced with HockeySDK 3.5, allowing for a seamless fallback if the user was not signed in or installed the app through iTunes or Xcode.