Crack the code, alone or head-to-head.
On a computer? Scan with your phone's camera to get the app.
Quick match, an open board of standing challenges, a six-character invite, turn-based play, or a challenge aimed at one friend.
Hunt one shared code together, or write the code your opponent has to break while they write yours.
No email, no password, no account to make. Solo boards work with no network at all and report themselves when you are back.
The Android version is in closed testing. Join in three steps, on the Google account you use on your Android phone.
Sign in and choose Join group. The group is only used to give you access to the test.
Open the groupOpen the test page and tap Become a tester.
Open the test pageNumber Guess appears on Google Play for your account, sometimes after a few minutes.
Open Google PlayAs the group owner I can see the e-mail addresses of members; I use them only to run the test. Found a bug or have an idea? Tell me on the support page.
A short clip recorded in the app.
A closer look at the app.
A soft, friendly take on bulls-and-cows: three, four or five digits, played solo or against someone else.
A friend is somebody who might be asleep. Play a guess at a time, whenever you both get to it.
A solve ends a duel only once both sides have had an equal number of turns, so moving first is never an advantage.
People are added by a code they read out to you — there is no searchable directory of strangers here.
Follows your phone, or override it in Settings. English and Turkish throughout.
A two-player take on the classic bulls and cows game. You crack a code of all-different digits (three, four or five of them); after every guess, green dots show right digits in the right place and yellow dots show right digits in the wrong place.
Yes, in five ways: a quick match against whoever is waiting, an open board of challenges, a six-character invite code, turn-based play at your own pace, or a challenge sent to one friend.
Solo games work with no network at all. Duels against other people need a connection.
No. There is no email, password or sign-up.
The Android version is in closed beta on Google Play; you can join it from this page. On iPhone it needs iOS 18.0 or later.
Other apps I have built.
Jump from a plane and fall all the way to space. Real freefall physics, dodge everything, unlock heroes.
A safe Mac cleaner: finds junk, app leftovers and duplicates, removes apps completely, and lets you undo every cleanup.
Crack secret codes by pure logic, then duel another operator in real time, build a mining empire, and raid rival syndicates.
Simplify your choices with Optio. The premium, ad-free cyberpunk decision-making experience for iOS.
The most fun way to speed up your mind, strengthen your reflexes, and push your math skills to the limit!
