Version 3.1.0 features comprehensive support for iPhone Duo, along with some other small changes. The changes in detail:

• The different displays and fold states of an iPhone Duo are supported in all orientations.
• When running with iOS 26 or later, overlay popups now have the close button in the top-left corner, instead of the top-right corner. This is in accordance with Apple’s Human Interface Guidelines.
• The sections of the introduction are now navigated by selecting from a menu. The older styling with tabs is still used when running with iOS 17 and 18.
• The Game Center access point is no longer shown on the main menu page.

Version 2.10.0 includes some enhancements to the Dark look, along with some small fixes and enhancements.

• When the Dark look is selected in the settings, it is now possible to choose whether the background for blocks is solid black or a lighter level of shading. When lighter shading is used, the other squares of the puzzle have a darker appearance.
• The option for blocks to be painted with a special fill effect has been extended to the Dark look too. Fill effects for blocks were introduced in the previous app version in connection with the new Extra Dark look.
• Improved the way the puzzle generator picks up the latest score from the leaderboard when returning to the app after a period of inactivity.
• Fixed an issue with updating the leaderboard for the puzzle generator after playing offline. The points earned offline were sometimes not being added to the leaderboard correctly.
• Fixed an issue where the page of settings for the puzzle generator was sometimes missing from the settings popup. This was happening if the settings popup was brought up while a puzzle was in play.
• If the squares between two blocks are selected using a swipe (drag) gesture, the selection can be inverted by tapping the corresponding clue value. This switches the selection from the squares inside the blocks to the squares outside the blocks. This was already possible before, but sometimes it would work with one tap, other times it took two. It now works consistently with just a single tap.
• A haptic effect is no longer triggered when multiple squares are selected using a swipe (drag) gesture.
• Some small cosmetic changes, including improvements to contrast ratios for the squares and numbers of a puzzle in play.

Version 2.9.0 includes a new lighting option for playing in complete darkness and a small refinement to the red filter. The changes in detail:

• A new “extra dark” look has been added to the lighting settings for when dark mode is active on the device. This form of look has been designed for play in complete darkness.
• When the new extra-dark look is selected, it is also possible to choose the fill effect that is used for painting the blocks of a puzzle. This can help to keep glare to a minimum and make it easier to recognise the blocks in the low-lighting conditions.
• Small adjustments have been made to the other forms of appearance too. In particular, the dark look has darker blocks and certain elements are less bright.
• The red filter level can be adjusted in much finer steps.

Version 2.8.0 includes some upgraded puzzle packs and various small improvements. The changes in detail:

• Many of the puzzles in the Scary puzzle pack category have been replaced with new puzzles that reflect the difficulty ratings more accurately. This applies to puzzles in the Assorted and Very Difficult packs, as well as the free selection. Players who already played the puzzles in these packs can now enjoy playing all the new puzzles at no extra cost.
• When a group of squares is selected using a drag gesture, any gaps in the same row or column are automatically filled, if possible. This works the same way as when a clue value is tapped, so blocks are added automatically if the number of empty squares exactly matches the number of missing blocks, or empty squares are populated with candidate values if two blocks are already present.
• When a group of squares is selected using a drag gesture, the combinations for the corresponding row or column are always shown automatically, even if no combinations were already showing.
• Fine tuning to the way the puzzle generator determines the difficulty of a new puzzle when running in Advanced and Expert play modes.
• The setting that allowed the puzzle generator to use permutation logic with “no limits” has been dropped. This used to be a way of generating more difficult puzzles, but the puzzle generator is now capable of generating very difficult puzzles without needing to resort to such measures. Puzzles that involved elaborate permutation checks were usually not much fun to solve anyway.
• More improvements to help explanations.
• Styling change to the panel showing the points scored for a completed puzzle. This panel now looks more like a button (iOS 26 and above). Tapping the panel is a quick way to view the leaderboard - this has always been the case, but until now it was less apparent that the panel is tappable.

Version 2.7.1 is a minor update with an improvement to the way the help works:

• When the help is used to provide a hint for a puzzle with pencil markings, the help is more likely to show how the pencilled candidates can be narrowed-down, instead of going straight to a follow-on step. This makes it easier to understand the logical reasoning for the follow-on step.
• This version also addresses a possible cause of some occasional crashes.

Version 2.7.0 addresses a usability issue when running with iOS 27 and includes some other small fixes. The main changes:

• The spotlight buttons react faster to the initial touch when running with iOS 27.
• A layout issue has been resolved when viewing the leaderboards on an iPhone in landscape orientation.
• An issue with jittery scrolling has been resolved when viewing the performance analysis for the puzzle generator on an iPhone in landscape orientation.

Version 2.6.0 features some usability improvements and styling adaptions. The changes in detail:

• Each clue of a puzzle is now shown as having the shape of a button. This makes it more apparent that the clue values are also buttons. The shapes also help to indicate that a button is available, even when a clue value is hidden (in this case, the button can be used to fill gaps in the associated row or column).
• The new button shapes for clue values can be turned off in the settings, if preferred. The setting can be found in the section “Layout & Appearance” under the heading “Puzzle clues”.
• When the setting to “allow combinations to be deleted individually” is turned on, the clue value that is currently selected is shown highlighted with an underscore. This makes it possible to see, which clue the combinations relate to. This is of particular significance when there are multiple clues with the same value.
• A usability issue concerning the panel with number combinations has been addressed. This panel sometimes overlaps the button for pausing a button, especially if playing on a small screen. Previously, this meant it was quite easy to tap the pause button by accident when trying to delete individual number combinations. An invisible buffer zone around the panel now stops this from happening (the panel is simply hidden instead).
• The red filter is supported more comprehensively. It now works for all forms of popup interaction too.
• Popup dialogs for confirming an action work better with large text sizes. This applies to the reset and help buttons when a puzzle is in play and to the buttons for selecting the level of difficulty for a new puzzle in the context of the puzzle generator.
• When the puzzle generator is running in Keep It Simple or Normal play modes and an 8x8 or 9x9 puzzle is generated on demand with a target difficulty of Very Difficult, it is more likely that the target difficulty will actually be achieved.
• The settings popup features some styling adaptions for iOS 26.

In version 2.5.0, more logic has been built into the puzzle generator and improvements made to the red filter. The changes in detail:

• When running in Expert play mode, the puzzle generator is able to generate puzzles that are even more convoluted than before.
• The red filter can now be added in all lighting modes. The filter also applies throughout the app, instead of just when playing a puzzle. This includes overlay presentations, such as when viewing a leaderboard, and (most) popup interactions. The red filter can be turned on in the settings under “Layout & Appearance”.
• A fix for an issue with the help function, which was occasionally failing to provide any help.

In version 2.4.0, ​the puzzle generator has more cunning and deleted combinations are restored when steps are undone. The changes in detail:

• More logic has been built into the puzzle generator, making it possible for it to generate puzzles that are even more challenging to solve! The new logic is used in Advanced and Expert play modes.
• When the Undo button is used to back-track the steps that have been played, any combinations that were deleted individually are now restored on a step-by-step basis. The same also applies when the help option “undo back to where I went wrong” is used. The ability to delete individual combinations is an optional feature that can be turned on in the settings.
• Some of the help explanations have been improved.

The 5-year anniversary celebration is coming to an end, so the app is reverting back to its regular look. We hope the special edition gave players some fun!

App version 2.3.0 is now available in the App Store. The extra puzzles that were added for the special edition are still included in this version too and players who already started playing the puzzles will be able to finish playing them, until the leaderboard resets again. The reset will happen on 9th March (UTC).

Other small changes in this version:

• The performance analysis popup features some styling adaptions for iOS 26. Some layout issues with this popup have also been fixed.
• When a clue value is tapped and empty squares are auto-filled with blocks, a warning symbol is shown if setting a block would cause an invalid arrangement. This will be the case if there are already two blocks in the intersecting row or column.
• A fix to prevent a crash from happening when resources cannot be loaded properly at app launch.