Have you considered using flow charting software? There is a program called “SimpleMind” available for both Mac & PC that is ideal for plotting and timeline development. Many of our writers work with just two apps. SimpleMind and Scrivener. In past NaNoWriMo events both of these are offered at a reduced cost to those who complete. Sometimes they are offered free for a month or so to allow you to complete the challenge. Being able to create a visual layout of chapters and characters can be very useful. I use those two programs for magazine layout and development as well as for structural editing.