Think before the whistle
Commit your read in writing: outlook, confidence and the factors that drive it. A written prediction is one you can learn from.
Private sports-analyst notebook
Read the game like an analyst.
Write a match read before kick-off, track the game as it unfolds, resolve it with the final score — and learn how well-calibrated your judgement really is. No odds, no stakes, no accounts. Just you, the game and the evidence.
Coming soon to the App Store
See how it works
- Works offline
- Data stays on your device
- EN · RU · BG
Live tracker · 67′
The concept
Not a betting app.
An analyst's notebook.
Estrelar is built for people who love to understand sport — why a team controls a game, when momentum shifts, and how honest their own predictions are. It rewards thinking clearly, not wagering.
Measure, don't guess
Hit rate is only half the story. Calibration with the Brier score shows whether your 80 % really means 80 %.
Private by design
No accounts, no ads, no trackers, no purchases. Your notebook lives on your device and leaves only when you export it.
OddsStakesMoneyAccountsAdsSubscriptionsTrackers
The core loop
Read. Track. Resolve. Learn.
Four steps per match. Repeat them across a season and a picture of your judgement emerges — where you're sharp, and where you're fooling yourself.
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Before the match
Read
Create a Match Read: teams, sport, competition, home / draw / away outlook, confidence from 50 to 95 %, key factors and notes.
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During the match
Track
Run the Live Tracker: a match clock and one-tap events per side — shots, chances, corners, fouls, cards — feeding a momentum chart.
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After the match
Resolve
Enter the final score. Estrelar scores your read, updates hit rate and Brier calibration, extends streaks and awards XP.
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Over a season
Learn
Confidence curves, goals, achievements and local recommendations such as “You are over-confident above 80 %”.
Rookie
Scout
Analyst
Strategist
★ Star Analyst
Inside the app
Four sections and a ★ quick action.
Pulse, Reads, Lab and Chronicle sit around a central star button that starts a new read, a quick note or the tracker in one tap.
Pulse
Pulse — your dashboard
A calm overview of how you read the game right now.
- Calibration ring and hit rate
- Rank, XP and streaks
- Weekly goal and smart tips
Reads
Reads — match notebook
Every prediction you've made, with reasoning attached.
- Search, sort and filter by sport or status
- Outlook, confidence and key factors
- Resolve with the final score
Live Tracker
Live Tracker
Log the match as it happens, one tap per event.
- Match clock with halves and pauses
- Shots, chances, corners, fouls, cards
- Momentum chart built from your taps
Lab
Lab — analytic tools
The classic models of sports analytics, ready to use.
- Elo calculator and Poisson score matrix
- Form index and Pythagorean expectation
- Team comparison and team lookup
Chronicle
Chronicle — the history
Ten editorial stories, from the 1859 box score to xG.
- Sabermetrics, Charles Reep, Elo, Corsi
- Interactive timeline and glossary
- A quiz to test what you've learned
Goals & Progress
Goals & progress
Personal targets that keep the habit alive.
- Weekly read goals and history log
- Achievements and analyst ranks
- Recommendations computed on-device
The interface
Designed like a match-day programme.
Navy, gold and clear numbers. Here are three screens from the app, rebuilt live in HTML.
Pulse
Your judgement, at a glance.
Pulse turns resolved reads into an honest scorecard. The ring shows your Brier score — the closer to zero, the better your probabilities match reality.
- Calibration ring. Brier score across every resolved read.
- Confidence curve. Stated confidence against actual results.
- Local insights. Tips computed on your device, never sent anywhere.
Reads
Every call, with its reasoning.
Reads keeps your predictions honest: written before kick-off, locked in, then scored against what really happened.
- Search, sort, filter. By sport, competition, status or confidence.
- Status at a glance. Open, live, hit or miss — colour-coded.
- XP for good process. Rewards resolved reads, not lucky guesses.
Lab
The models analysts actually use.
Enter expected goals for each side and the Poisson tool builds the full score matrix — plus home, draw and away probabilities — instantly and offline.
- Six tools. Elo, Poisson, Form index, Pythagorean, Comparison, Team lookup.
- Explained, not hidden. Every tool shows its formula and caveats.
- Feeds your reads. Use results to sharpen your confidence.
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Screens
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Analytic tools
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Languages
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Trackers
Privacy
Your notebook is yours alone.
There is no Estrelar server holding your data. Reads, events, goals and settings live in local storage on your device.
- No registration. Personalised onboarding — language, sports, level, weekly goal — without an account.
- No analytics, ads or trackers. Nothing reports what you do.
- Export or wipe. Download everything as JSON, or erase it in one step.
- Works offline. Online lookups are optional and only on your tap.
External services
Two optional lookups. Fully transparent.
Estrelar only goes online when you explicitly tap a lookup. Requests carry no keys, no identifiers and no personal data, time out quickly and fall back gracefully when you're offline.
TheSportsDB thesportsdb.com
Public sports database used by Lab → Team lookup.
- When
- Only when you type a team name and tap Search.
- What is sent
- Only the search text you typed — nothing else.
- What returns
- Club info: founded year, stadium, league and badge.
- Images
- Badges load from TheSportsDB's image CDN only when results are shown.
Wikipedia REST API wikipedia.org
Used by Chronicle → Read more on articles.
- When
- Only when you tap Read more under an article.
- What is sent
- Only the page title, in your chosen language (EN, RU or BG).
- What returns
- A short public summary of the topic.
- Offline
- A friendly fallback message; the rest of the app keeps working.
These third-party services receive your device's IP address as part of any normal web request, under their own privacy policies. Estrelar never sends them your reads, notes, settings or any identifier.
FAQ
Questions, answered.
No. Estrelar has no odds, no stakes, no money, no wagering and no links to bookmakers. It is a notebook for analysing sport and measuring how good your own predictions are. It contains no gambling of any kind.
No. There's no registration or sign-in. A short onboarding asks for your language, favourite sports, analyst level and weekly goal — all stored only on your device.
In local storage on your device. Nothing is uploaded. You can export everything as a JSON file or wipe it at any time from Settings.
A measure of how well your stated probabilities match outcomes. It's the average squared difference between your confidence and what happened: 0 is perfect, 0.25 is what a coin-flip would earn. Lower is better.
Yes. Reads, the Live Tracker, Lab calculators, Chronicle articles, glossary and quiz all work without a connection. Only the optional Team lookup and Wikipedia “Read more” need the internet.
Reads and the tracker work for football, basketball, tennis, ice hockey, volleyball and more. Lab tools are sport-agnostic models, and Chronicle covers the analytics history of several sports.
English, Русский and Български. You choose during onboarding and can switch anytime in Settings.
No. There are no subscriptions, no in-app purchases and no ads.
Adults who enjoy sports analytics — fans, writers, coaches and students who want to think more clearly about games. Sound and motion can be tuned in Settings, and reduced-motion preferences are respected.
Support & contact
Questions or feedback?
We read every message. Include your device model and what you were doing — but never send us your exported data unless you choose to.
The next match is a chance
to read it better.
Open Estrelar, write your first read and see where your judgement stands.
Coming soon to the App Store
Read the FAQ