"Preview Mockups on Devices in Realtime" - Does this say exactly what you want it to say, because it's the very first thing I read, and I need to understand it before I read any further. What this said to me, on first impression, is a way to see final renders of a URL on different browsers and running on different devices. Only later am I thinking this connects to Photoshop actually?

Scrolling down, I don't understand the huge picture of a bird. Switch the white to transparent, the blue to white, and put it small in the top-left corner I think. But you know it looks too much like twitter, you probably will want to change it. One random suggestion to make it distinct; add a tablet with a wireframe, and the hummingbird is feeding off it.

"Hummingbird lets you preview designs and webpages from your computer on devices in realtime." Did you consider adding the word 'target' almost anywhere you say devices? Is it "designs and webpages" or "webpage designs"? Is it devices, or browsers? I guess "devices' browsers" actually.

Maybe a table with what devices you support. I think that would make it immediately clear what you were doing. You could also have a 'Preview' which shows how you used hummingbird running against your own site.

"Hummingbird works on Android and on any browser that supports websockets (Safari on iOS, IE 10 on Windows Phone, Chrome and Firefox on desktops...)." OK, now reality is starting to sink in. I'm going to need to possess each one of these devices... and have it setup and configured... It's not really HTML Preview Service.

It would be nice to mention you are releasing under MIT license on the main page. I looked for the source for Android and iOS builds, but it's not up on Github yet, so I guess at this point it's not quite fully released. But everything is brand new as of today, so no problem to wait and see when it comes.

I'd love a screen capture of the installation process, and example output. Even better, show me how this fits in your workflow and how it makes you work faster. If you can fit a compelling demo in under a minute, I would put it at the top/center.

I think it would be cool on the site to tell us if this is a hobby project, MVP, or what are YOUR goals with this? Just switch into first person and go for it :-)