I’ve been using iconping for years and it rocks. Sadly it doesn’t cater to all my needs and I was eager to contribute back. After seeing there are some pull requests and issues waiting for years, I decided to fork and incorporate all pull requests including my own. You can download iconpong from here.
This bookmarklet provides an easy way to test css styles against a website without access to its server by creating a <link/>element in the <head> of the page. It also updates it with an cache-blocking parameter if already exists.