StepMenus 0.3 for Mac was available to download 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 program is included in Theming Tools.
From the developer:
StepMenus enhances the user experience in OS X by providing a NeXTSTEP-style applicaiton menu for Cocoa applicaitons. The current application's menu is displayed in a compact floating window that can be repositioned wherever is most convenient. It is great for multi-monitor setups since you no longer have to move the cursor (and your attention) to the main monitor to access the menu for a window on your secondary display.
You may want to check out more Mac applications, such as Occurrence Selector, which might be similar to StepMenus.