This app is new variant of Sudoku. This variant is called "Kawaii Sudoku". Kawaii Sudoku has some small blocks. Please see screenshots. It seems baby face of Standard Sudoku. It is so Kawaii.
The board of "SDK Kawii" is sized 6x6, and it has 9 plots(= small blocks) sized 2x2. Digits cannot repeat on each column, row, and plot.