A community created list of projects to improve your Java skills.
Projects:
| Name | Category | Difficulty (1-5) | Type* | 
| Blackjack Game | Games | 2 | learning | 
| Sudoku/Tic Tac Toe Solver | Games | 2 | learning | 
*Type is whether the project is an open source one that people can contribute to or if it is a small, learning project that someone would just make on their own.