Give me a good concept mapping app and I'll keep myself busy for hours. iThoughts just added a really nice way to create attractive rainbow colored maps and I think it's great.
That's pretty cool. You can set the start color and let it make something great for you based on the chosen color palette or tweak the "Range" and get a variety of tones based on the number of nodes to color.
I'm really happy with the way iThoughts 2 is working out (previous review).
iThoughts | Universal | Currently $2