I had a couple of clients I created iOS applications for and had to upload their apps to the iTunes connect for them. The upload is done using the tool called “Application Loader”, which is installed together with Xcode 3.2.5 and later. The tool itself is located under /Developer/Application/Utilities/Application Loader . However, once logged in, there is no out of the box way to log out! I.e. if I’ve uploaded the app for client A and now I want to upload for client B from the same computer, I’m stuck since the Application Loader logs in automatically to the client A account.

Here is how to do it manually:

1. Close Application loader (Command + Q)
2. Navigate to ~/Library/Preferences and delete 2 files called com.apple.itunes.connect.ApplicationLoader.LSSharedFileList.plist & com.apple.itunes.connect.ApplicationLoader.plist 
3. Start the Application Loader once again – it should be asking you for the login and password! Done!