Sudoku Buddy
The joy is in figuring it out.
Keep your pencil. Keep your puzzle. Get a little help when you need it.
Sudoku Buddy is an Android companion for standard 9×9 Sudoku on paper. Scan a
puzzle—including the answers you have already written—check the reading, and
ask for a hint that explains the next move. It is made to help with the puzzle
already on your page, not replace it.
Website ·
Usage guide ·
Support ·
Privacy
See the app
These are real Android screens; the current release may differ slightly.
See more on the website.
Get the app
Google Play — Android: Get Sudoku Buddy.
As of 29 October 2026, version 1.0.4 (code 243) is active in both Production
and Internal testing. It needs Android 8.0+ and a camera. Invited testers can use
the internal-test opt-in.
Version 1.0.5 (code 244) is attached to an unsubmitted Internal testing draft
and is not available to testers.
No public APK is published in this repository.
What it helps you do
- Read printed clues and handwritten progress, then correct a misread square.
- Check your answers and reveal a hint in stages, with the relevant cells and
solving technique highlighted.
- Reopen saved puzzles from on-device history and continue after a break.
Scanning, checking and hints work on the phone, including offline. Handwriting,
erasures and lighting can cause misreads, so review the recognized grid before
relying on a check or hint.
Support, feedback and bugs
Get support ·
Share feedback ·
Report a bug
GitHub issues and attachments are public. Remove personal details from reports
and use the private contact option in the support guide for a photograph or
example you do not want to post publicly.
Privacy and release status
Privacy policy ·
Local-data deletion
Camera recognition and puzzle history stay on the device. Users can submit an
uncertain-reading report to Freevia for private recognition analysis and training; reports
include the puzzle photo, recognition results and corrections. Automatic sharing
is optional and off by default. The app has no account, ads, routine usage
analytics or ad tracking. See the privacy policy
for report handling and deletion details.
Sudoku Buddy's original source code and documentation are licensed under
Apache License 2.0. Freevia and Sudoku Buddy names and logos remain
subject to their respective trademark rights; the license does not grant branding
or endorsement rights. Third-party components retain their own licenses; see
the notices and bundled license texts.
For contributors
The SwiftUI iOS port shares Kotlin recognition, solver and teaching logic, with
native scanning, durable history, localization and consent-based feedback. Open
iosApp/SudokuBuddy.xcodeproj; see iOS development
for setup and tests, and App Store preparation for the submission packet and remaining account/device gates. The iOS preview supports
camera/photo scanning, manual entry, checking, hints, and on-device history with
automatic puzzle and progress restoration after restart. It also includes the
71 Android language catalogs, launcher artwork, offline notices, and Android
overlay colors in a dark SwiftUI interface. Review scanned cells
before play; the iOS capture path still needs validation on a physical iPhone.
The Android app uses Kotlin, Jetpack Compose, CameraX and OpenCV, with separate
modules for recognition and deterministic solving. Use JDK 21 and Android SDK
platform 36. From the repository root:
.\gradlew.bat build
On macOS/Linux, use ./gradlew build. The usage guide
and Play preparation notes provide more
detail. A passing local build is not a Play release.
