I'm a software engineer and a personal finance nerd, and I've spent the past 6 months building Ifso, a planner that shows how your financial decisions play out.
I started Ifso because I wanted to see how a few decisions I was weighing would actually turn out, and the existing tools weren't quite what I was looking for. They were complicated for simple things, and it felt like I had to do a lot of learning just to get off the ground. Beyond that, modeling simple moves (selling a house, changing my monthly contributions from a given year on, etc.) was unexpectedly hard. What I fundamentally wanted was to just tell the simulator "here's what I want to do, how does it end up for me?"
I built Ifso around that philosophy: you enter your finances today, put in the decisions you're looking to make, and see how it plays out and whether you'd be on track to reach your goals. My goal was to make it as easy to use as possible and keep the complexity hidden away, while still giving you as much insight as possible. You can use Ifso without signing in. Nothing to link and no bank login, so everything is typed in by hand, and your plan is saved in your browser. If you want your plans across devices, you can always sign in for free. Your data is never shared, and you have total control over your data, so you can download or delete it at any point if you'd like.
Behind the scenes, the simulation engine handles all of the calculations for you. It automatically runs through investment account growth, loan amortization schedules, income taxes, capital gains, retirement account rules, etc, and then you get a straightforward answer on how the plan works out in the end. You can also run Monte Carlo simulations to stress test a plan, build a second plan with one thing changed and compare the two side by side, and more.
A big part of the user experience is that actions live where you'd expect them. If you want to sell a house in a given year, you go to that house and simulate selling it right there. If you want to increase your retirement savings, that option lives right on the retirement account itself. The same idea carries through the rest of it, where you can convert a property into a rental as an action on the property itself, view a year's cash flow as a visual diagram from that year, or turn a decision on and off to quickly see how it changes things.
If you have any thoughts, suggestions, or any feedback, please let me know. Feedback from users has been an integral part of getting Ifso to where it is today, and I'd love to keep making it more helpful!
Landing page, where you can find a more comprehensive list of features and functionality: https://ifso.io
Try the planner without signing in: https://ifso.io/try