Kolba

From an atom to the universe: 450 chapters. Tilt your phone and the world slides behind the tubes. A calm, ad-free ball sort puzzle.

Kolba is a calm ball sort puzzle. One new puzzle every day, the same one for everyone, and a journey of chapters to play at your own pace.

Move balls between glass tubes until every colour sits in a tube of its own. A group of the same colour on top moves together. Some puzzles add a jar: it holds one group at a time, locks to the first colour you put in it, and has to be empty when you finish. That one rule changes how you plan.

A journey from an atom to the universe: behind your tubes, each run of 30 chapters is one step up in scale. You start inside an atom, pass molecules, cells, a leaf, a meadow and a forest, rise above the clouds, circle the Earth and the Moon, and sort your way out to the stars, a galaxy and the whole universe. Tilt your phone and the world slides gently behind the board.

• 450 numbered chapters: finish one and the next is a tap away. Tubes, fog that hides what lies underneath, tubes of different heights, and a Challenge every tenth chapter that you can skip for now and come back to • Soft music, off in Settings • A new daily puzzle at midnight, the same for everyone, easiest on Monday • Past days: every puzzle you missed waits in the archive, with no penalty • A short tutorial that teaches by playing, not by reading • Hints that nudge before they tell, and undo as far back as you like • A score from your moves against par, with no timer on the daily • A quiet month view of the days you played, with no streak to lose • Ball styles (clay, glass or jelly), ball palettes and backgrounds to suit your eyes • Colour-assist symbols, high contrast, reduced motion and VoiceOver support • Optional Game Center leaderboards and achievements • Optional iCloud sync of your lessons and finished days • A widget, a Control Center control and a Siri shortcut for today's puzzle • In English, Turkish, Spanish, Portuguese, French, German, Hindi, Russian and Indonesian

No ads. No purchases. No account. No tracking. Kolba works fully offline. Nothing goes to us: iCloud sync goes to your own iCloud, Game Center only if you turn it on.