MetaFlow 1.2 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. The application lies within Productivity Tools, more precisely Office Tools. The actual developer of this free Mac application is Graphical Memes Software Inc. We recommend checking the downloaded files with any free antivirus.
From the developer:
MetaFlow is a tool for creating flow network diagrams, also known as Sankey diagrams. Metaphorically, the diagrams depict a set of tubes through which fluid flows. Each tube runs between two stages in the flow, and connects with other tubes at one of the junctions located within each stage. The width of a tube is an indication of the amount of fluid passing through it per unit time.
You may want to check out more Mac applications, such as pdf-DocPro, PDFViewer or Instant PDF, which might be related to MetaFlow.