The best thing to create is User Stories regarding the functionality that you would like and use an Agile Development process to prioritize and refine things as you build it. That will act as your todo list for functionality. I would also highly recommend wireframing all the major parts of your ...
You know I have never come across such tools. I did get a chance to work with an entrepreneur who has ADHD, I served as his business adviser. Our setup was that he did not spend time on things unless we talked about it first and I held him to super tight schedules. It workout great! His tool sale...