Help for your next puzzle

Support

How to play, answers to common questions, and a direct line to us.

Need a hand?

Contact

Email us at [email protected]. For a bug report, include your iOS version, device model, what you were doing when it happened, and—if possible—a screenshot or screen recording.

Email support

The simple rule

How to Play

Choose the numbers to keep and make the totals for every row, column, and colored area match their targets.
Tap a tile to mark it as a number to keep. Tap it again to remove your selection.
There is no separate action for marking numbers to remove. Numbers you do not select can simply stay as they are.
As you choose numbers, the remaining totals go down. A row, column, or colored area shows a check when it reaches zero.
Choose all the numbers that belong in the solution to clear the board. There is no time limit.
Choosing a number that should be removed is recorded as a mistake, but there is no limit or game over. Unselect it and keep playing.
A hint watches a rewarded ad and then sets one undecided tile to its correct state. Hints are unavailable while ad inventory is loading.

Good questions

Frequently Asked Questions

Does every puzzle have a unique solution?: Yes. Every generated board is checked by the solver and accepted only when it has one solution.
What happens if I tap the wrong number?: It is recorded as a mistake, but the puzzle does not fail and there is no game over. Tap the tile again to undo your selection.
What is a “?” tile?: It is a hidden number. You can determine whether to keep it from the other totals without seeing its value. Hidden tiles appear at higher levels.
How do hints work?: After an optional rewarded ad, one undecided tile is set to the correct state. Wait for an ad to be ready if the hint button is unavailable.
Why are there ads, and what kinds are shown?: Just Sum! is free and supported by Google AdMob. Ads may be App Open, adaptive banner, interstitial, or rewarded ads.
Does the app track me or show a consent prompt?: Google UMP may show a regional consent message, and Apple ATT may ask for permission when needed. You can revisit available Privacy Options in the app settings.
Where is my progress saved?: Your level progress, statistics, achievements, and settings are saved on this device. There is no account sync.
How do I reset my progress?: Delete and reinstall the app. This removes the locally stored game data from the device.
Which languages are supported?: Japanese, English, Spanish, Korean, Simplified Chinese, and Traditional Chinese.
Which iOS versions are supported?: Just Sum! requires iOS 17 or later.

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