SmartPaste 4.0 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. The actual developer of this free software for Mac is Mihhail Lapushkin. SmartPaste for Mac lies within Productivity Tools, more precisely Clipboard Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
SmartPaste is an application that pastes without annoying styles. Every time you copy styled text, say from the web, SmartPaste automatically cleans out all unwanted styles, while keeping the useful ones. To be specific, SmartPaste keeps styles like Bold, Italic, Links, Headings, and Lists and cleans out unwanted styles such as Text foreground colors, Text background colors, Text shadows, Fonts, and Text sizes.
You may want to check out more software for Mac, such as AutoClips, ReClip or MayaMaya, which might be related to SmartPaste.