Octile is a logic puzzle inspired by Archimedes’ Stomachion — one of the oldest known mathematical puzzles, dating back to around 250 BC. Fill an 8×8 board using 11 tiles. Three gray tiles are already placed. Arrange the remaining 8 colored tiles to cover every empty cell — no gaps, no overlaps. MATHEMATICALLY DESIGNED PUZZLES Octile’s 91,024 puzzles are derived from 11,378 base configurations discovered through exhaustive search. Each base puzzle generates 8 variants via D4 symmetry (rotations and reflections). Every puzzle is solvable. HOW TO PLAY • Drag and drop tiles from the tray onto the board • Tap a tile to select it, then tap an empty cell to place it • Tap a selected tile again to rotate it 90° • Drag a placed tile off the board to return it to the tray FEATURES • 91,024 logic puzzles (11,378 base × 8 symmetry transforms) • 3 visual themes — Classic, LEGO, and Wood • Pause & resume — timer stops, board is masked • Auto-pause when app goes to background • World scoreboard — compare anonymous scores (no chat or direct messaging) • Hints — up to 3 per puzzle when you're stuck • Achievements — unlock milestones as you play • Puzzle pacing system — encourages short play sessions • Bilingual — English and Traditional Chinese (繁體中文) • Works offline — 88 built-in puzzles available without internet; connect to unlock all 91,024 • Clean, minimal design Scoreboard uses anonymous identifiers and stores only gameplay results. PAY ONCE, PLAY FOREVER No ads. No subscriptions. No in‑app purchases. One purchase unlocks all puzzles and features. THE STORY In 250 BC, Archimedes devised the Stomachion — a square divided into 14 pieces. The question of how many ways the pieces can fill the square remained open for centuries, until modern computation helped researchers enumerate the solutions. Octile reimagines that spirit on an 8×8 grid. After exhaustive search, we discovered 11,378 base configurations — with rotations and reflections, that's 91,024 playable puzzles for a focused, minimal logic experience. Archimedes had ivory. You have pixels. The challenge lives on.