Download of SmileAllDay 2.3.10 for Mac was on 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. SmileAllDay for Mac relates to Internet & Network Tools. The actual developer of this free software for Mac is Evan McNulty.
From the developer:
SmileAllDay is a Safari extension which intelligently redirects the shopper to smile.amazon.com as appropriate. This Mac application offers a convenient way to share SAD with you, but you don't need to run it for the extension to work. The tool is compatible with Amazon's API content delivery network.
You may want to check out more Mac applications, such as NetZero, Watson or Choosy, which might be similar to SmileAllDay.