I had the students use simple mind to create mind maps and it worked quite well. The students needed little instruction to create the map and it took them about 5 min to get the first part done. Since the semester just started, I decided to have students create a graphic organizer for the topic such as quadratics, similar triangles, exponential and logarithmic functions and simple inequalities for 4 different classes. The first part that was added was the material we covered this week. For instance, the first offshoot for quadratics was one that dealt with graphing, x and y intercepts, vertex, domain and range, max and min. As we go through the chapter, we'll add more offshoots until the whole chapter has been studied and mapped so the students see the whole picture. About half my students are classified ELL so I am hoping this activity helps to increase their understanding of the concepts.
Simple mind is a free app that is so easy to use and seems quite intuitive for the students to use. They really enjoyed using it. I know this is not the only free mindmapping app but it is the one I am using.