App Profile: K.O. Sudoku - Sudoku Solver

Various types sudoku puzzles, answers, step-by-step explanations, allow take photo to input.
It supports 3/4/5/6/7/8/9/10/12/15/16 grid sudoku, jigsaw sudoku, killer sudoku, kendoku, skyscraper sudoku, clone sudoku, odd/even sudoku, 3D sudoku, samurai sudoku, flower sudoku, windmill sudoku, gattai sudoku, butterfly sudoku, cross sudoku, twodoku, triple doku, sohei sudoku, compdoku, fortress sudoku, kropki sudoku, product sudoku, ratio sudoku, sum sudoku, VX sudoku, 56 sudoku, balanced sudoku, consecutive sudoku, non-consecutive sudoku, touchless sudoku, anti-knight sudoku, diagonal sudoku, percent sudoku, window sudoku, asterisk sudoku, girandola sudoku, center dot sudoku, pyramid sudoku, offset sudoku, etc.
There are also technique tutorials and a rich online sudoku store.
---------------
K.O. mode: Provide the solution directly.
Help mode: Provide step-by-step explanations.
---------------
Sudoku Rules: Fill in the 9x9 grid with numbers 1~9 such that each row, column, and 3x3 box contains each number exactly once.
Jigsaw Sudoku: Fill the grid with numbers 1~9 such that each row, column, and irregularly shaped box contains no repeating digits.
Killer Sudoku: The number on the dashed line signifies the sum of the digits within the corresponding cage, and the digits within the cage must be unique.
Kendoku (Newdoku/Calcudoku/Mathdoku): Fill in the numbers 1~n, ensuring that no digit is repeated in each row or column. Additionally, the number and arithmetic symbol (+-×÷) located at the top left of each group represent the answer obtained by performing the specified operation on the digits within that group. If no operator is specified, it means this group can use any of the above operators.
Skyscraper Sudoku: External clues that indicate the number of visible buildings from each direction (taller buildings block shorter ones, i.e., larger numbers obscure smaller numbers). Unmarked directions have no restrictions.
Arrow Sudoku: The number in the circle equals the sum of all numbers along its arrow path.
Clone Sudoku: Using colors to mark multiple identically-shaped clone regions, where numbers in corresponding positions across clone regions must match.
Odd / Even Sudoku: Cells with circles must contain odd digits, cells with squares must contain even digits.
3D Sudoku: Constructed by stacking 27 individual 3x3 boxes in a three-dimensional grid, intersected by 6 colored lines (red, orange, yellow, green, blue, purple). The goal is to fill the grid with numbers 1~9, ensuring that each 3x3 box, as well as the 9 cells along each colored line, contain unique, non-repeating digits.
Samurai Sudoku: Formed by overlaying five 9x9 standard Sudoku grids, positioned at four corners and the center. The objective is to fill the grid with numbers 1~9, satisfying the standard Sudoku rules in each of the five independent regions.
Compdoku: Adds symbols such as great than, and the numbers must satisfy the corresponding size relationships.
Fortress Sudoku: Gray fortress cells must contain numbers larger than adjacent white cells.
Kropki Sudoku: Kropki Sudoku: Black dot - ratio of 2; White dot - differ by 1; Others - not satisfy either of these two relationships.
Product Sudoku: The small numbers marked on the grid indicate the product of the two adjacent cells.
Ratio Sudoku: Marked hints on the board indicate the proportional relationship between the numbers in those two cells.
Sum Sudoku: The small numbers marked on the grid indicate the sum of the two/four adjacent cells.
Consecutive Sudoku: The difference in numbers between grids on both sides of a barrier being 1, and the difference between two grids without barriers definitely not being 1.
Diagonal Sudoku (X Sudoku): Adds to standard rules by requiring uniqueness of digits in two major diagonals.