Settings

Tap the gear icon ⚙ in the top bar to open Settings. Each setting takes effect as soon as you change it.

Language. Until you choose one, the app follows your device's language if that language is one of the app's, and uses English if it is not. To choose, use the bar across the top of Settings. It has a button for each language the app speaks, named in its own language. The first button, a phone, is “Use the device's language”: it goes back to following the device. Your choice changes the whole app, this help included, and is remembered.

Below the bar, in the order Settings lists them:

Sound effects
Turn the game's sounds on or off: the applause for a clean win, the ta-da for any other, and the click when Check locks on.
Win animation
Flash the grid colors when a puzzle is solved: the full flash for a clean win, solved from the start with no peek at a hint and no check that showed a mistake; a single flash otherwise.
Left-handed keypad
Move the digit buttons to the left side when the keypad sits beside the grid. You can also drag the keypad handle to switch sides.
Show timer
Display the elapsed time above the grid, or beside it when the keypad is beside the grid.
Show progress
Display a dot for each cell, filling in as you solve: a row above the grid, or a block beside it when the keypad is beside the grid.
Enable hints
Show the hint button 💡 in the action bar below the digit buttons.
Hint arrows
Draw arrows between the linked cells of a hint. Off shows just the circled and slashed candidates and the highlighted parts of the board.
Cell highlighting
Make the cells that hold the selected digit glow. Always off while a hint is showing.
Auto-answer
Off: disabled. Touch: tap a single-candidate cell to fill it. Auto: single-candidate cells fill themselves.
Bug reporting
Show the red ! button on every screen. Off by default, and while it is off the app never contacts a server at all. Tap the button to open a form for telling us what went wrong. The report goes to bugs@sudokux4.com with a picture of the screen, the puzzle as text, and any photo the puzzle was read from. Drag the button wherever it is out of your way. Include diagnostics, checked by default, adds details such as the build and the platform.
Color scheme
Earthy (parchment brown), Marine (marine slate), Classic (plain newsprint), or Midnight.
Animation speed
Speed of the pen/pencil flip animation: Teleport, Fast, Med, Slow, or Crawl.
Split view
Only where there is room for two panes: a tablet, or a large window on a computer or in a browser. On by default, it puts the album on the left and the game on the right; turn it off to use the phone layout.
Slideshow
Only while Split view is on. Step through the album one game at a time, life size, before opening one. Off by default: tapping a game in the album opens it.
Manual game generation
When you add a game, choose its kind and difficulty in a dialog, instead of drawing a ready-made puzzle from the pre-generated queue.

At the very bottom of Settings, a line of small print names this copy exactly: its release, build number, and build date, and “Beta test” on the copies from sudokux4.com, the web version among them. You can select and copy it for a bug report. The title bar of the album's front page shows the short form, such as “Sudoku X4 (v2.13.1 build 6030)”, or just “Sudoku X4 (v2.13.1)” where the bar is too narrow for the build number, as on an iPad held upright.