I was JUST looking for something like this yesterday. Could become very useful if you keep at it, I'll definitely be checking back from time to time. One minor nitpick: perhaps normalize the height of your snippets in the main grid view?

Thanks ! what do you mean normalize the height, like make it adapt to the height of the screenshot? Like pinterest or something?

I guess what he means is have the previews all have the same height instead of the same width. Currently, you basically can't discern anything on the very wide examples.