To install it:
git clone https://github.com/cz/snipt-chrome-extension.git
Then head over to Chrome, and click Window -> Extensions. Check the "Developer mode" checkbox, and click "Load unpacked extension". Find the folder you just cloned down and save. Once installed, click the "S" (http://cl.ly/3Y3P3u1Z3s3t23271u0d) and click the little avatar icon in the top right. Enter your username and API key (you can find your API key on https://snipt.net/api/), and save.
Then, enjoy! If you have issues with the extension, file an issue on GitHub.