My Take
The tool is useful for exploration of how mind-mapping works. As the instructor maps out a project, the flow of the work is outlined and additional details can be realized. So, the map helps the instructor to understand the requirements of the project.
The collaboration between students would realize the true value of the application. However, the company is changing the business model, which makes it difficult to adopt. This is a relatively new direction made in the Summer of 2014. When using the free account you can expect to see the following message often: "This is a Professional feature". The pricing ranges from $36/year per user to $180/year per 25 users. This means you can still share your mind map with your students by providing their email addresses, but you cannot make your mind map public and use advanced features.
How I Use It
I used Mindomo as a tool to illustrate a final project workflow. While I have a text documentation for the project, including detailed steps, the mind map allows me to abbreviate the process and illustrate it. I can include pictures and icons, which help students to understand the complexity of the project. The workflow is established from subject to subject by using various arrows (called relationships in Mindomo).
The project includes a web site design, creation, and publishing. The mind map helps to outline the idea generation phase and the subsequent tasks. it is often difficult for students to understand how to get started or what the next step should be. The "map of the project" makes the process clearer.
The mind map can be exported as a PDF, which is needed in the free version of the account.
An advanced way to use the system is to allow students to create their own accounts and collaborate on creation of mind maps. They can document this way their work on the project. They can also collaborate as a group on brainstorming ideas.