Shape Box 3D
The last couple days I have been trying to get into 3D, but then I realised something. You code from top to bottom (yes, you can code in multiple files, but that's besides the point) and when I made a game like Tic Tac Toe in Console, you print out line by line depending on your code. Now with GUI, you still code in one direction, but the output is in 2D. Sometimes I still struggle to keep understanding my code with all the different panels, elements and other GUI parts. Now with 3D, I had absolutely no clue how certain lines of code would influence the final output (especially everything around rotation). This Shape Box has all primitive shapes (box, cylinder and sphere), with a setting for each property in the panel on the right. Even though it might not be that exciting for the average user, it still helps me understand and visualize the mechanics of 3D.