One of my projects resulted in me creating a deck manager application. I saw a Java based one made for "Magic the Gathering" that seemed to have what I needed. Sadly for me it was based on the Eclipse RCP.
Therefore, I tasked myself with recreating it in a more generic way so that it can be modular and support other games as plug-ins. It turned into Deck Manager:
The project is here: https://sourceforge.net/projects/deck-manager/
Right now it doesn't have any of the deck managing features yet but it's looking good.
It just updates from the internet and retrieves pictures for display.
If you like it and want to help just let me know by writing to me here: email@example.com