An eBay BIN/OBO best offer reveal tool.
Bonobo simply adds a 'Get sale price' link to eBay listings which were sold after the seller accepted a best offer. By default eBay does not show the actual sale price, it's hidden behind a page which isn't easily accessible. This extension just links through to that page for you.
You can rest assured that this extension has no tracking, does not perform any data monitoring or URL changing and will only work on eBay and no other website.