SUDOKU - 5700 original puzzles app for iPhone and iPad

・5700 puzzles, all of which are original.
・Beautiful puzzles (they are designed in various forms)
・Cunning traps and original logic puzzles.
・To improve logical thinking ability and memory.
・All puzzles were created by the puzzle designer Naoki Inaba. They are not automatically generated puzzles.
・Hybrid operation that allows you to choose both number-first and cell-first methods.
・Sudoku Palace is the official sponsor of the Japanese national team for the World Sudoku Championship. *Held every year

■■8 levels of difficulty■■
Beginner
Novice
Intermediate
Advanced
Challenge
Challenge+
Ultimate challenge
Ultimate challenge+

■■Explanation on how to solve all the puzzles■■
・Full House
・Hidden Single
・Naked Single
・Locked Candidates
・Hidden Pairs
・Naked Pairs
・Naked Triples
・Hidden Triples
・X-wing
Explanations of all puzzles using novice to advanced solving techniques, complete with diagrams (uses Coins)

■■Improved Hint function■■
・In addition to showing the correct number, there will also be an explanation on why that number is the correct option.

■■Functions On the settings page■■
・You can write down candidates for each cell
・You can set the background colour to your favorite colour
・You can turn sound effects on or off
・You can change the colour of the selected number to make it easier to spot
・You can highlight rows, columns and blocks with different colours
・You can adjust the placement of the numeric keypad
・Auto-save
・Start Over, Undo, and Reset buttons
・Enter All Candidates and Delete All Candidates functions
・Checker function to check if the number is correct (uses Coins)