adFinder
This utility implements a script that finds ads based on common ad sizes.
The information about ad sizes and position of those ads are logged to the console and stored in Firebase. The Firebase data from previous runs of the script can be publicly accessed here
The code can be used as a bookmarklet by creating a bookmark to a link with the code in bookmarkletedAdFinder.js as the URL of the bookmark
Alternatively you can build the bookmarklet by using this utility, however that is not compatible with arrow functions, so if you're going to use that utility please use the code in bookmarkletCompatible.js