ODEVI
A NEW KIND OF NUMBER PUZZLE
Small islands. Big discoveries.
Odd and even make islands. Find where they belong in a fresh logic puzzle with one clear rule set—and exactly one solution.
Discover how to play
Free to play on iOS. No account needed.
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A little odd. A little even. All connected.
MEET YOUR NEXT BRAIN BREAK
Three rules. Endless aha moments.
01
Every number, once.
Fill each row and column with every number exactly once. Start small with a 4×4 grid.
02
Same parity. Same island.
Neighbouring cells that are both odd or both even join together. Up, down, left and right—not diagonally.
03
Little clues. Big meaning.
A small corner number tells you how many cells belong to that island. Use it to piece everything together.
From your first clue to your first solve.
Take a closer look at the rules and the tools that help you put every island in its place.
01 / The goal
02 / Odd and even islands
03 / Read the corner clues
04 / Mark odd and even cells
05 / Watch your islands grow
06 / Spot a mistake
07 / Use the optional counters
08 / Get a helpful hint
09 / Fill in the numbers
10 / Enjoy the solved-it moment
11 / Choose your next challenge
A closer look at your next obsession.
Make yourself at home
Learn by doing
A nudge in the right direction
Ready for Expert?
That solved-it feeling
LESS GUESSING. MORE DISCOVERING.
Two spare minutes. Or one more hour.
Learn the basics in a short tutorial, then follow your curiosity from quick 4×4 puzzles to Expert 7×7 challenges.
One solution. Always.
Every puzzle is checked by computer. There’s exactly one answer, reachable by logic—not luck.
Hints that teach.
Don’t just get an answer. Understand the reasoning and learn a new technique for next time.
Room to work it out.
Mark odd and even cells, watch islands take shape, and undo or check your work whenever you like.
A QUIET MOMENT FOR A CURIOUS MIND
Find your next aha.
ODEVI is free to play, with short ads between puzzles—never in the middle of your thinking.
ODEVI · Odd & Even Islands · For iOS
KEEP THE IDEAS. LOSE THE ADS.
Just you and the puzzle.
A one-time Remove Ads purchase removes every ad and unlocks unlimited hints. No subscription.
$9.99 one-time purchase
Available inside the app. Local prices may vary.
ODEVI / Odd and even make islands. © 2026 ODEVI