Decision journal

How good is your gut, really?

Write down what you expect and how sure you are. On the due date DecideKit asks “Did it happen?” – and shows your hit rate, Brier score and calibration. Plus the tools good deciders use. All on your phone.

No account
Stays on your phone
Free to start

Coming soon to Google Play.

Coming soon to the App Store.

Forecasts screen with hit rate 74 %, Brier score 0.17, a calibration chart from 50 to 99 % and the verdict “Overconfident”

You remember your hits.
Not your misses.

Hindsight rewrites every story: “I knew it all along.” A written forecast with a number keeps you honest – and shows where your gut is right and where it fools you.

How it works

Forecast. Wait. Find out.

One sentence, one number between 50 and 99 %, a due date and an area. Thirty seconds – and the forecast is locked in, exactly as you meant it.

On the due date you get a reminder: did it happen? Yes or no – your score updates right away.

New forecast: “The client will say yes to the offer”, 80 % sure, check in 1 month, area Work

50–99 %

how sure you are, in steps of one

calibration buckets from 50 to 99 %

days of quarantine for every new idea

Six tools for better decisions.

Forecast journal

Statement, probability, due date. Hit rate and Brier score show how good your predictions really are.

Calibration

Of everything you call 80 %, do 8 in 10 happen? The chart says overconfident, too cautious or well calibrated. By area with Pro.

Pre-mortem

Imagine the project failed. Name at least three reasons, a countermeasure for each and check-in dates with reminders. Pro.

Idea quarantine

New ideas wait 14 days. Then three hard questions: Who pays? First step? What do you drop? Build, park or let go.

Mistake library

Write each lesson down in five minutes, with keywords. When a new forecast fits, DecideKit shows you the lesson again.

Coin-flip oracle

Stuck between two options? Flip the coin – and notice whether you feel relieved or disappointed. That is your answer.

Tools

Good ideas survive 14 days.

Every new idea goes into quarantine first. When the countdown ends, three hard questions decide: build it, park it or let it go. The stats show how many ideas really were worth it.

Plus assumptions with test and deadline, and a pre-mortem before every big step.

Idea quarantine: two ideas locked with days left, one ready for review, and the stats built, parked, let go

Every day

One question a day. A lesson that sticks.

“Today” shows what is due, what you learned this week and a lesson of the day – your own or one of 20 built-in rules of thumb.

No account, no cloud, no AI. Your forecasts and lessons never leave your phone.

Today screen with a forecast due for a verdict, Yes/No buttons, the weekly review and the lesson of the day

The difference

Decide with feedback, not hindsight.

“I knew it all along”Forecasts written down with a number
No idea if you are overconfidentCalibration chart and a clear verdict
Every shiny idea started at once14 days of quarantine, then three hard questions
The same mistake twiceLessons that come back when they fit
Notes scattered across apps and cloudsOne private journal, only on your phone

For everyone who decides.

Founders

Test assumptions before you build and keep shiny ideas in quarantine.

Managers

Run a pre-mortem before every big project and learn which calls you get right.

Freelancers

Will the client say yes? Will the project finish on time? Find out how good your estimates are.

Money decisions

Write down why you buy or sell – and check later whether your reasons held up.

Students and career

Exams, applications, offers: forecast the outcome and learn how well you judge yourself.

Everyday choices

Move or stay? Buy or wait? The coin-flip oracle reveals what you already want.

Quick questions.

Who is DecideKit for?

For anyone who makes decisions and wants to get better at them: founders, managers, freelancers, students – or anyone who wants to know whether their gut feeling can be trusted. One forecast a day is enough to start.

What does DecideKit cost?

Free: 10 open forecasts with hit rate, Brier score and calibration, 3 ideas in quarantine, 10 lessons, the coin-flip oracle and the weekly review. Pro adds unlimited entries, calibration by area, pre-mortem, the assumption tracker, backup and CSV export – as a monthly or yearly subscription (yearly with a 7-day free trial) or a one-time purchase. The price is shown in the store.

How does DecideKit make money?

Only through the optional Pro upgrade. There are no ads, and no data is sold.

What is a Brier score?

The standard measure for forecasts: the squared distance between your probability and what happened. 0 is perfect, 0.25 is what you get by always saying 50 %. Lower is better – and it rewards being sure only when you are right.

Do my entries leave my phone?

No. Forecasts, ideas, lessons and notes are stored only on your phone. There is no account and no cloud. The app only sends a technical usage signal with a random installation ID – never your entries. Backups are files you share yourself.

Does DecideKit make decisions for me?

No. There is no AI and no advice on what to choose. DecideKit gives you structure and honest feedback on your own judgement, so you learn from every decision. It is not financial, legal or medical advice.

Why only 50 to 99 %?

Every forecast is phrased as the outcome you think is more likely. If you are below 50 %, simply write the opposite. And 100 % would mean you cannot be surprised – the whole point is to learn where you can.

Which devices and languages are supported?

Android and iPhone – the app is in preparation and coming soon to Google Play and the App Store. It speaks English, German, Spanish, French and Italian, including the built-in rules of thumb.

What do you expect to happen this week?

Write it down, put a number on it and let DecideKit ask you later. Your first forecast takes about 30 seconds.

Coming soon for Android and iPhone.