Mycroft can't tell you what to do.
But he can tell you what will happen if you do.
How it works
Six tabs. One complete picture of your financial life — and every branching future you can imagine.
IRL
Start with your actual financial life — accounts, income, expenses, debts. Your IRL baseline is the gold line: where you actually are, not where you hope to be. Everything else branches from here.
What-Ifs
Create parallel scenarios from your IRL baseline. Retire at 45 or 67. Buy the house or keep renting. Take the promotion or start the business. See the dollar difference, across decades, on one chart.
Plot Twists
Raises, layoffs, kids, mortgages, divorces, retirements. Every life event is a plot twist that shifts the trajectory. Add them to any scenario and watch the ripple propagate across decades.
Weave
Mycroft runs 500 simulations on every projection, modeling the range of likely outcomes — not just the rosy one. Volatility drag included. (Yes, that's real.) All futures on one chart.
Dreams
Lived the Dream rewards real IRL progress. Weaver Dreams rewards planning depth. From Daydreamer to Legend. No confetti for doing nothing.
Local-First
Everything runs on your machine. No cloud sync, no account required, no telemetry. The only thing that leaves your device is your license activation — a brief handshake, nothing more.
Export
Export a polished PDF report for your spouse, your advisor, or yourself in five years when you've forgotten the math. Pop the chart to a second monitor for Zoom calls. Mycroft signs every page.
The Engine Has a Name
He doesn't connect to the internet. He doesn't call home. All the math — every simulation, every projection, every sensitivity analysis — runs on your machine, with your numbers, in private.
What Mycroft does, very well, is take those numbers and tell you where they go. Five years. Ten years. Forty. Every assumption visible. Every result auditable. No cloud, no accounts, no "just trust the algorithm."
Mycroft notices when your credit cards grow faster than your income. He notices when your savings rate won't get you to retirement on time. He notices when cash has been sitting idle long enough to cost you something. He notices when a spending habit is quietly doing more damage than it looks like on any given month.
He doesn't judge any of it. But he notices.
Mycroft Engine · TANSTAAFL Labs · Computed locally on your machine
Inside the app
Click a tab to see what it does. Click any screenshot to enlarge.
click to enlarge
📊 Dashboard
Net worth, monthly income, monthly expenses, total assets, total liabilities, health score on a scale of 1000. The Dashboard is your honest snapshot — no flattery, no smoothing, no positive spin.
Your Dreams progress sits right at the top. Wherever you are on the journey from Daydreamer to Legend, it shows.
click to enlarge
💸 Cash Flow
Income in. Expenses out. The Cash Flow tab is the monthly mechanics that underlie every scenario — broken down by category, with rollups for the patterns that matter and the leaks you've been ignoring.
Edit any number to see Mycroft re-run the entire projection in real time.
click to enlarge
✨ Weave
The Weave tab is the big picture. Every What-If you've defined, plotted against your IRL baseline. Monte Carlo confidence bands when you want them. Plot Twists marked as events on the timeline.
Forty years on a single line of sight. End-of-period summary below. Pop it out to a second monitor for the family conversation.
click to enlarge
🔀 Plot Twists
Each What-If is a parallel future built from a sequence of Plot Twists — life events you place across the timeline. Promotions, layoffs, kids, home purchases, car loans, retirements. Every one is a year you pick and an amount you set.
Adjust the sliders on the right — investment return, inflation, raises, surplus allocation — and the projection re-flows.
click to enlarge
⚙ Customize
Sixteen color themes (yes, sixteen — light, dark, cream, plum, forest, navy, and more). Custom accent colors. Timeline horizon. Simulation depth. Currency formatting.
Tune the look until What-If Weaver feels like your tool, not someone else's.
What it shows you
Six examples of what Mycroft surfaces once your numbers are in.
click to enlarge
📊 Dashboard · Proactive debt warnings
He flagged it in red. He was polite about it.
When credit card balances start growing faster than income, Mycroft puts a red box on the Dashboard the moment you open the app. He prints his usual notice underneath: "Mycroft notices. He doesn't judge. But he notices."
click to enlarge
✨ Weave · Recovery scenarios
When IRL trends the wrong way, the alternatives become obvious.
Plot two or three recovery paths against a baseline that's heading negative. Watch the dollar gap widen across the five-year horizon. The intervention scenario isn't always the obvious one — but it's always plotted, with the end-of-period numbers right underneath.
click to enlarge
✨ Weave · Category-level analysis
Find the category that's quietly eating your future.
Trace a million-dollar trajectory difference back to a single spending bucket. The IRL line slumps to negative; one habit change recovers six figures; a full audit recovers seven. Same income, different choices, all plotted side by side.
click to enlarge
🔀 Plot Twists · Long-form decision modeling
Make the pattern visible.
Map ten or twenty Plot Twists across a decade — promotions, leases, loans, payoffs, raises — and the rhythm hiding inside high income and low savings becomes obvious. Slide the right-hand parameters and the entire projection re-flows.
click to enlarge
✨ Weave · 5-year horizon
Pause investing to kill the card, or keep going?
Two lines. One honest answer. Mycroft ran both — Minimum Payments ends at $64K, Nuke the Card ends at $66K — and the gap is smaller than you'd think. It's not always obvious which one wins, which is exactly the point.
click to enlarge
✨ Weave · Worst-case modeling
What if the market does nothing for twenty years?
Mycroft has thoughts. They are not optimistic. Drop the return assumption to zero, hold inflation steady, and watch the lines flatten. It's the question every honest planner asks and almost no plan answers. Now it does.
Pricing
What-If Weaver · Full License
One-time · Windows · License key via email
No subscription. TANSTAAFL — There Ain't No Such Thing As A Free Lunch, except for the updates, which are.
Secure checkout via LemonSqueezy · Instant license key delivery
Questions
.whatifweaver file anytime for backups or to move to a new machine.Windows · One-time purchase · Yours forever