Sudoku ++ for Android

This version was not for me. I play Sudoku to relax and I can't relax with a timer in my face. It's too bad there wasn't an option to disable it. This version may be good for someone who enjoys racing againt a clock. But, for me, it adds stress and just defeats my purpose of relaxation.

There are multiple grids that are incorrect. They tell me to add a number that is already in the box. Easy to use but not accurate.

The keyboard work to interact with the game, but otherwise this is the mobile game on a larger screen. No guides but the interface is not too difficult. One file came up as un-installable but the game still works without it.

does not work as well. Crush always.

There is no indication -- and no way to find out -- what the changing colors of the numbers mean. When I finish a row, the background changes color, but it does not stay changed. It's difficult to keep track of what I have already completed. I am new to Sudoku and it would help to have some visual aids. This game seems to have them, but won't tell me what they are!