This is a desktop Mobilize application. It has a GUI but most of the user interactions happen using a CLI (Command Line Interface).
It is a Java sample application intended for students learning Software Engineering while using Java as the main programming language.
It is written in OOP fashion. It provides a reasonably well-written code example that is significantly bigger (around 6 KLoC)than what students usually write in beginner-level SE modules.
What’s different from level 3:
A more sophisticated GUI that includes a list panel and an in-built Browser.
More test cases, including automated GUI testing.
Support for Build Automation using Gradle and for Continuous Integration using Travis CI.
Some parts of this sample application were inspired by the excellent Java FX tutorial by Marco Jakob.