TrollKuSix levels of difficulty
From Easy to Diabolical and Insane. Every puzzle is graded by the solving techniques it takes, so each level feels the way it should.
Sudoku for iPhone & iPad
A troll is watching your next move.
Clean, fast sudoku from easy to insane, with hints that teach real solving techniques and a daily puzzle to race your friends on.
Coming soon on theApp Store
Everything a sudoku game should be
No ads in your way, no clutter. Just good puzzles and a troll who's quietly rooting for you.
A daily challenge
One puzzle per difficulty each day, the same for everyone. Post your time and see how you stack up.
Hints that teach
Stuck? TrollKu points to the pattern, from naked singles up to X-Wing, Swordfish and XY-Wing, so you learn it for next time.
Colour pencil marks
Every digit has its own colour, so candidates, pairs and the last spot for a number jump right out.
Scan a puzzle from paper
Point the camera at a newspaper or puzzle book and play it on your phone. Recognition happens on your device.
Game Center leaderboards
Best times for every difficulty and every daily puzzle, with your friends through Game Center.
Beat your best time
TrollKu keeps your personal best for each difficulty. Set a new record and the troll throws you a party, confetti and all.
Support
Answers to common questions. If yours isn't here, get in touch.
How do I import a puzzle from a newspaper or book?
Tap Scan, take a photo of the puzzle with the grid filling most of the frame, then check the recognised digits and fix any the camera misread before you start.
Will hints just give me the answer?
No. A hint shows you where a solving pattern applies and names the technique, so you can make the move yourself.
Can I choose which hint techniques are used?
Yes. In Settings you can switch each technique on or off, from naked singles through X-Wing, Swordfish, XY-Wing and BUG.
My times aren't showing on the leaderboards.
Make sure you're signed in to Game Center in the Settings app on your device. Scores post when a puzzle is finished while you're signed in.
Will I lose my game if I close the app?
No. Your puzzle in progress is saved on your device and restored the next time you open TrollKu.
Privacy policy
Last updated October 8, 2026
TrollKu is made by TrollSoft LLC. TrollKu does not collect, store or share any personal information. The app has no accounts, no analytics, no advertising and no tracking, and it doesn't send your data to us or to any third party.
Data stored on your device
Your settings, your puzzle in progress and your daily challenge history are stored on your device. Deleting the app removes them.
iCloud
If you're signed in to iCloud, your best times, solve counts, badges and troll rank are synced through your own private iCloud account so they follow you to your other devices. This data is stored by Apple under Apple's privacy policy, and we can't see it. If you're not signed in to iCloud, it stays on your device.
Camera
If you choose to scan a puzzle, TrollKu uses the camera to take a photo of it. The digits are recognised on your device using Apple's Vision framework. The photo is not saved or uploaded anywhere.
Game Center
If you're signed in to Game Center, TrollKu submits your puzzle times to Game Center leaderboards. Game Center is operated by Apple and governed by Apple's privacy policy. We don't receive your Game Center information.
Children
TrollKu is suitable for all ages and doesn't knowingly collect information from anyone, including children.
Changes
If this policy changes, we'll update this page and the date above.
Contact
Questions about privacy? Email info@trollsoft.dev.