Clarify was built by Blue Mango Software, the company behind the widely-loved documentation service Screen Steps. The company says that Screen Steps traditionally aimed for both documentation and communication; Screen Steps will from this point on focus on documentation and Clarify will be the communication product. For now Clarify is free and it seems to work pretty well.
I had some authentication issues and I feel like the screen capture mode is a little slow to initiate, but it's cool. I like the idea. I think I'll try to use if for an extended period of time and see how useful it is. I'm not excited about composing emails outside of Gmail with Rapportive, but I've been typing up a few emails with images, publishing them to the Clarify website, then copying the contents and pasting them into Gmail.
I suspect that many people would appreciate a service like this for composing emails. Here's what it looks like.