# R-MAP Crux — Decide, or learn why not yet

> Decision analysis tool that prioritizes information value before preference. (iPhone/iPad app by Francisco Mavungo.)

- Source: https://appshunter.io/ios/app/r-map-crux/id6801779659 (this page in markdown: same URL + `.md`)
- Developer: [Francisco Mavungo](https://appshunter.io/developer/1885212034)
- Category: Business, Productivity
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 18.0 · 2 MB
- Languages: American English
- Released: 2026-08-20
- Data updated: 2026-09-04
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/r-map-crux/id6801779659/reviews.md

## What is R?

Every decision tool on earth helps you pick between options. Almost none of them will tell you the truth that matters more: that you are not ready to pick at all, and what it would cost to become ready. CRUX does both, in that order.

THE FRAME
A decision is options against an uncertainty. Name the states of the world and how likely you believe they are, then state each option's payoff under each state as a range - minimum, most likely, maximum. Ranges become distributions; you never name one.

DOMINANCE FIRST
Before asking anything about your preferences, CRUX tests first-order stochastic dominance across the whole distribution. When one option is at least as good at every percentile of every outcome, it says so in plain language: your risk tolerance is irrelevant to this choice. The strongest claim a decision analysis can make, and most tools never check it.

THE VERDICT CAN BE "NOT YET"
CRUX computes the expected value of perfect information - what resolving the uncertainty first would be worth. When that number is large next to the decision itself, the verdict is not a recommendation. It is: premature. Deciding today leaves money on the table, and here is the figure.

PRICE A REAL STUDY
Perfect information does not exist, but pilots, surveys and expert opinions do. Set how often a study would be right and CRUX prices it. If the study costs less than it is worth, buy the information before you buy the decision.

THE BREAKEVEN PRIOR
You said the market adopts with 45% probability. CRUX tells you the answer flips at 50% - and asks how sure you are of that number. Most disagreements about decisions are actually disagreements about probabilities, and this makes them visible.

PREFERENCE, ASKED LAST
Only when dominance and information cannot settle it does CRUX ask about your risk attitude. One slider. Certainty equivalents re-rank live: the sure amount each gamble is worth to you, not just its average.

REPRODUCIBLE BY SEED
Every analysis runs from a printed seed. Share the report and anyone with CRUX and your frame reproduces every number exactly.

CALIBRATION
Ranges people state are too narrow. CRUX can widen every payoff range by a factor you control - and if you track your forecasting record in R-MAP Caliber, free on the App Store, your measured overconfidence is the right factor.

FREE AND FULL
Free: the complete worked example decision plus one decision of your own. One purchase unlocks unlimited decisions and study pricing. No subscription.

PRIVATE BY DESIGN
Everything stays on your device. No account, no sign-in, no analytics, no tracking. The only network activity is the App Store purchase itself, handled by Apple.

Built by R-MAP LLC.

## Key features

- Decision analysis with uncertainty
- Dominance checking
- Value of perfect information calculation
- Study pricing
- Breakeven probability analysis
- Risk preference assessment
- Reproducible analysis with seeds


## Frequently asked questions about R

### What is R-MAP Crux?

R-MAP Crux is a decision analysis tool that helps you evaluate options against uncertainties. It prioritizes checking for dominance and the value of information before asking about your risk preferences.

### How does R-MAP Crux handle uncertainty?

It allows you to define states of the world, their likelihoods, and the payoffs of each option under those states as ranges, which are then converted into distributions.

### Can R-MAP Crux tell me if I'm not ready to decide?

Yes, if the expected value of perfect information is significant compared to the decision itself, R-MAP Crux will indicate that deciding now is premature and show you the potential cost.

### How does R-MAP Crux price a study?

You can set how often a study would be correct, and R-MAP Crux will price it. If the study's cost is less than its worth, it recommends acquiring that information before making the decision.

### Does R-MAP Crux have ads?

No, R-MAP Crux does not contain advertisements. It is designed for privacy, with no account, sign-in, analytics, or tracking.

### What devices is R-MAP Crux available on?

R-MAP Crux is available on iPhone and iPad devices.

### How often is R-MAP Crux updated?

The latest version, 1.0.1, was last updated on August 27, 2026, indicating recent development activity.

### What is the age rating for R-MAP Crux?

R-MAP Crux has an age rating of 4+, making it suitable for a wide range of users.

## Version history (last 2 releases)

### 1.0.1 — 2026-08-27

Price an imperfect study on any decision, not just two-outcome ones.
A new Log tab records what you decided and what actually happened,
then scores your forecasting: Brier score, reliability curve, and
whether your probabilities run high. Steadier dominance testing,
faster analytics, and notes that travel with your options.

### 1.0 — 2026-08-21

No release notes.

## More apps by Francisco Mavungo

- [FM Alerts](https://appshunter.io/ios/app/fm-alerts/id6760596758)
- [R-MAP Caliber](https://appshunter.io/ios/app/r-map-caliber/id6798137560)
- [R-MAP Ideon](https://appshunter.io/ios/app/r-map-ideon/id6798545683)
- [R-MAP Keystone](https://appshunter.io/ios/app/r-map-keystone/id6801757735)
- [R-MAP Aegis](https://appshunter.io/ios/app/r-map-aegis/id6801780003)

All apps by Francisco Mavungo: https://appshunter.io/developer/1885212034

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-04.*