How are the difficulties decided?

Each puzzle is graded by the hardest solving technique it needs, not by how many numbers are missing. Beginner and Easy can be solved by scanning alone, with no pencil notes. Medium adds squares where only one number fits. Hard brings in pairs, triples and pointing. Expert needs X-Wings, Swordfish and XY-Wings, and Fiendish goes beyond those. Each technique is explained when you unlock it, and you can reread them in Settings → Techniques notebook.

I bought Supporter. How do I get it back on a new phone?

Open Settings → Supporter → Restore purchases, signed in to the same Apple ID or Google account you bought it with. It usually comes back on its own the next time the app connects.

Will my progress move to a new phone?

Your progress is saved on your phone, not in an account. Restoring your new phone from an iCloud or Google backup of the old one brings it across. Moving between iPhone and Android does not carry it over.

How do I turn the daily reminder on or off?

Go to Settings → Daily reminder. You will get at most one a day, and none once you have played that day's puzzle. If it does not arrive, check that notifications are allowed for Flouri Sudoku in your phone's settings.

What happens to my streak if I miss a day?

You earn a streak freeze for every seven-day run, and you can hold two. A freeze covers a missed day automatically. Supporters can also catch up on past daily puzzles from the calendar; those stamp the day but do not extend a streak.

Can I change how ads use my data?

Yes. Use Settings → Privacy choices (shown where it applies) and your phone's tracking and advertising settings. Supporters see no ads. The privacy policy has the details.