This app lacks the ability to check build status, manage internal and external testers, or assign which builds are ready for testing or release. These functions need to be done from the website.
However, the iTunes Connect website isnt designed for mobile. Many pages, including the welcome page, do not render correctly on an iPhone. You would think all Apple sites would be optimized for mobile, especially sites related to iOS.
Even the functionality that does exist in the app doesnt always work correctly. The counts in the lists dont match the graphs. The status indicators on the main page dont match the product pages.
I also agree that for non-developers, the iTunes Connect branding is confusing. The description could be more clear that a developer account is required.