The 1.1 version of springIt! for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Design & Photo Tools, more precisely Viewers & Editors. This Mac app was originally produced by ReelPath LLC. We recommend checking the downloaded files with any free antivirus.
From the developer:
With springIt! anyone can create complex animations with Final Cut Pro X in seconds. Design incredible moves your audience will notice using the ReelPath spring engine. This is not a collection of canned templates, this is a fully featured animation plugin built with Motion. Create an unlimited range of styles unique to your project with the in-depth toolset included in springIt!
You may want to check out more Mac applications, such as Smith Chart for Mac, Movie2Shot or TVPaint Animation, which might be related to springIt!.