Moodstream by Getty Images is apparently a brainstorming tool designed to help you find inspiration, whether it's for images, videos, audio or just new ideas. You can create your own moodboard or select some predefined ones.
Currently having a lot of fun with it, brilliant stuff.
I think I'd probably use it more for zoning out or background noise when I'm working than actual brainstorming. I'm also waiting for the day that Mercer starts getting pelted with rocks on-screen.