Comp is a must have app for any Adobe CC user – Adobe Comp Review

You can toss away the napkins folks! Comp is the quickest way to get layouts out of your head and into your CC app of choice: InDesign, Muse, etc. The ability to hook into Adobe Stock and TypeKit lets you bring in imagery and typefaces which you can easily tweak when you get back to your desktop. If you're a CreativeCloud user you owe it to yourself to try this out.
Review by bdsheehan on Adobe Comp.