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no-bs-sudoku

ongoing

open source sudoku app. no ads, no paywalls, no bs.

mar 14, 2026 – nowsolo: product, design, full-stack
flutterflutter_blocdriftgo_routerfl_chart
github

a design-forward sudoku app built with flutter. dark, minimal, fast. zero ads, zero paywalls, zero dark patterns. every feature is free. hints are free. no premium tier. no 'watch an ad for a hint'. the grid is the hero, everything else gets out of the way.

how it works

  1. 1pure dart puzzle engine generates puzzles with guaranteed unique solutions using constraint propagation and symmetric hole-digging
  2. 24 difficulty levels, pencil notes with auto-clear, full undo stack (every action reversible, including hints)
  3. 3intelligence engine tracks solve velocity, mistake patterns, consistency. surfaces one smart insight per day, not notifications or badges
  4. 4daily puzzle rotates difficulty by day of week (mon/tue easy → sun expert), seeded generation means no server needed

key decisions

pure dart puzzle engine, no external solver

the entire generator, solver, and board model is written from scratch. constraint propagation + symmetric hole-digging gives guaranteed unique solutions without depending on any external library.

drift over raw sqlite

type-safe sqlite for local persistence. every game state, stat, and insight is stored locally. fully offline, no network calls, no backend dependency.

intelligence over gamification

no badges, no streaks-as-pressure, no notifications. the quality score (0-100) and velocity analysis give real feedback. daily insights like 'you solve best in the evenings' are quiet observations, not engagement tricks.

terminal aesthetic

near-black OLED background (#0A0A0A), electric lime accent (#C8FF00), DM Mono for numbers, Space Mono for UI. lowercase everything. 'Solved.' not 'Amazing!! You did it! 🔥'. the copy voice matches the design: dry, calm, no exclamation points.

what i built

  • puzzle engine with unique solution guarantee (constraint propagation + symmetric hole-digging)
  • game screen with full undo, pencil notes, smart highlighting, 3 free hints per puzzle
  • daily puzzle with day-of-week difficulty rotation, deterministic seeded generation
  • intelligence engine: quality score, velocity analysis, daily insights
  • stats dashboard with 14-day sparkline, 90-day github-style heatmap, per-difficulty breakdown
  • auto-save with floating resume bar and full state restoration

timeline

mar 14, 2026

started

every sudoku app is either ad-infested or paywalled. just wanted a clean one.

mar 16, 2026

completed. in beta testing