3 free software
Getting software for free is a bonus.
Here are a few that I recommend.
XMind. Is a free, open source, mind mapping and brainstorming tool. This comprehensive mind mapping tool helps you to express, structure and organise your ideas, then present them in attractive, professional diagrams. http://www.xmind.net/
Wunderlist is the easiest way to get stuff done. Whether you’re planning a holiday, sharing a shopping list with a partner or managing multiple work projects, Wunderlist is here to help you tick off all your personal and professional to-dos. https://www.wunderlist.com/
GanttProject: This software allows you to easily organise tasks and time frames. GanttProject is an industrial-strength cross-platform (Windows, OS X, Linux) project manager that provides everything you need to stay in control. Create and organise tasks, add milestones, set priorities and costs, allocate resources, monitor your colleague's workload: it's all here. http://www.ganttproject.biz/