Three, that I’ve just found. LOVE!
August Empress. She has great tutorials, sells beautiful blog elements (you may recognise some here) and runs an online blog design course!
colr.org. Feed any photo to this clever app, and it will come up with a colour scheme complete hex codes for you to use on your blog, or any other creative project.
PicMonkey. Cool photo editing tools, plus a bunch of instragam-esque filters.