I managed not to spend any money on calculators or financial planners. And at this stage of the plan, I have completely lost interest in modeling.
But earlier, I was a very regular user of the linear programming based i-orp tool. I consulted with James, the creator, to add features, and did some testing. Although James and his tool are both gone now, there is another tool that's linear programming based, called owl planner that I've tried. It's open source and as with i-orp, not out to make money. Although my motivation to model has dropped off, I managed to do some modeling on the new tool. I don't like that there's nowhere to put your house. You can define an inflow, but I liked the way i-orp worked better. If I were interested enough, I could change the code myself and offer a pull request, or fork the project and put it on a server myself, but not that's not the way I want to spend my time.
But it's my opinion that if you plug your data into a lot of models, and try out a bunch of different assumptions, you get a pretty accurate picture of what lies ahead.
