BetterSearch 1.9 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The application is included in Internet & Network Tools. This free Mac application was originally created by Carlo Zottmann.
From the developer:
An extension for Firefox which enhances Google (all international flavours, too), MSN Search, Yahoo Search, A9, Answers.com (web results), AllTheWeb, Dogpile.com, del.icio.us and Simpy.com bookmarks by adding previews (thumbnails) and Amazon product images and info (type, price, rating for US/DE/UK/CA/FR products), a quick preview feature as well as "Open in New Window", "Site Info" and "Wayback Machine" links to the search results.
You may want to check out more Mac applications, such as Delete Flash Cookies, Subio or RSS Checker, which might be similar to BetterSearch.