# Calibrate: Forecast Journal — Brier score and calibration

> Brier score and calibration (iPhone/iPad app by Yoshifumi Sato.)

- Source: https://appshunter.io/ios/app/calibrate-forecast-journal/id6794981990 (this page in markdown: same URL + `.md`)
- Developer: [Yoshifumi Sato](https://appshunter.io/developer/6780413827)
- Category: Productivity
- Price: $2.99
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English
- Released: 2026-08-05
- Data updated: 2026-08-15
- User reviews in markdown: https://appshunter.io/ios/app/calibrate-forecast-journal/id6794981990/reviews.md

## What is Calibrate?

Calibrate is a forecasting journal for anyone who wants to make better decisions. Instead of trusting your gut, you write down what you think will happen, how confident you are, and when you'll know — then let the math tell you how good your judgment really is.

Inspired by superforecasting and the rationality community.

MAKE A PREDICTION
Write a clear question, set your probability from 1% to 99%, and pick a resolution date. Add notes and categories to keep things organized.

RESOLVE IT HONESTLY
When a prediction comes due, mark it true or false (or void it if the question no longer applies). Calibrate keeps you honest by separating what you predicted from what actually happened.

SEE YOUR BRIER SCORE
Your Brier score measures how accurate and well-calibrated your forecasts are — lower is better. Track it over time and watch it improve as you practice.

READ YOUR CALIBRATION CURVE
The calibration curve shows whether your 70% really happens about 70% of the time. Discover if you are overconfident or underconfident, and by how much.

STAY ON TOP OF WHAT'S DUE
Open, due, and resolved views make it easy to see what needs resolving and review your track record.

PRIVATE AND OFFLINE
No sign-in, no ads, no tracking, no network access. Everything stays on your device.

One simple purchase. No subscriptions.


## Version history (last 1 release)

### 1.0 — 2026-08-05

No release notes.

## More apps by Yoshifumi Sato

- [おけいこ月謝帳 教室の集金管理](https://appshunter.io/ios/app/id6787108752)
- [DualShot: Front & Back Cam](https://appshunter.io/ios/app/dualshot-front-and-back-cam/id6788761561)
- [Progressly – Body Progress](https://appshunter.io/ios/app/progressly-body-progress/id6789591055)
- [Holdly – Isometric Timer](https://appshunter.io/ios/app/holdly-isometric-timer/id6789790139)
- [かんじ1年生 小学1年の漢字ドリル](https://appshunter.io/ios/app/1-1/id6789917332)
- [かんじ3年生 小学3年の漢字ドリル](https://appshunter.io/ios/app/3-3/id6790055787)

All apps by Yoshifumi Sato: https://appshunter.io/developer/6780413827

---

*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 2026-08-15.*