Super - this will certainly come in handy at some point, though I was primarily looking for browser screenshots at the moment (which I think your animockup doesn't do today)
Awesome. And indeed, I do plan on adding more mockups + the option for people to make their own (selecting the area where the video would be placed). It seems like there is some demand.
The Web Archive seems to imply that BrowserFrame is about a year older than Screely, though.
[1] https://www.screely.com/