LOL! I love their short but sweet description:
Red Pen lets you upload your design, share a short URL, and get live, annotated feedback super-fast. It remembers you— there’s no logging in, no project management, no bullshit.
This is the deal: you retain ownership of your uploads. Your data will not be sold or shared. We will never ever spam you.
Because we are not douchebags.
The beautiful thing about this simple and very useful service is how dead-easy and how obvious it is to use.
There’s something brilliant about simplicity, right?
Done and done.
Check out Red Pen. Brilliant.