MindMeister is described as 'The market-leader in online mind mapping. Unlike traditional mind mapping tools, MindMeister allows for real-time brainstorming sessions between an unlimited number of users and requires only a standard web browser' and is a very popular Mind Mapping tool in the office & productivity category. There are more than 100 alternatives to MindMeister for a variety of platforms, including Web-based, Mac, Windows, Linux and iPhone apps. The best MindMeister alternative is AFFiNE, which is both free and Open Source. Other great apps like MindMeister are LibreOffice - Draw, yEd Graph Editor, Xmind and Miro.