[seancron]

You have two options:

1. Use the code from Github instead of the Chrome webstore

2. Open up the code on your computer once you download and verify it against Github.

[mnmldave]

Author here. Yes, you can get the original (rather messy) code from https://github.com/mnmldave/scraper. There are brief installation instructions in the README.

It should be noted that the javascript is passed thru Google's Closure compiler before packaging, in case you're looking to verify.