App 被退回，原因是
Guideline 4.2 – Design – Minimum Functionality
We found that the usefulness of your app is limited by the minimal amount of content or features it includes.
Next Steps
We encourage you to review your app concept and incorporate different content and features that are in compliance with the App Store Review Guidelines.
We understand that there are no hard and fast rules to define useful or entertaining, but Apple and Apple customers expect apps to provide a really great user experience. Apps should provide valuable utility or entertainment, draw people in by offering compelling capabilities or content, or enable people to do something they couldn’t do before or in a way they couldn’t do it before.
似乎是 App功能太簡單，需要增加更多功能，或畫面要再複雜一點。呵呵呵。