iSilhouette 1.0 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 program lies within Audio & Video Tools, more precisely General. We recommend checking the downloaded files with any free antivirus.
From the developer:
iSilhouette is a video filter that colorizes the silhouette of an object. You can define up to 4 colors that iSilhouette will add up and use for the creation of a shape. The shape and the surrounding areas will be colorized by two defineable colors. Additionally the borders of the shape can be colorized.