I have found the computer programme Electric Quilt a great help for designing quilts since I bought my EQ4 ten years ago. I've used it, and later versions to plan my quilts, decide on sizes of blocks and borders, colour choices and much more. And of course I design all sorts of fanciful quilts I know I'll never actually get round to make, but that's half the fun. Much better than any computer game, if you ask me!
Different versions of my X-block quilt in EQ - see the finished quilt here.