OmniGraffle is described as «can help you make eye-popping graphic documents-quickly-by providing powerful styling tools, keeping lines connected to shapes even when they»re moved, and magically organizing diagrams with just one click» and is a very popular app in the office & productivity category. There are more than 50 alternatives to OmniGraffle for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and Chrome OS. The best alternative is diagrams.net, which is both free and Open Source. Other great apps like OmniGraffle are Pencil Project, yEd Graph Editor, LibreOffice — Draw and Dia.OmniGraffle alternatives are mainly Mind Mapping Tools but may also be Diagram Editors or Prototyping Tools. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of OmniGraffle.