First of all, for all those who are not familiar with this game I would like to introduce you with the basics. Sudoku (Single Number) is a combinatorial, number placing (from 1 to 9), logic game. The goal of the game is to fulfill the 9 x 9 grid, and 3 x 3 subgrids with numbers only from 1 to 9. One number can only feature in one row, one column in one of the nine 3 x 3 subgrids.
Sudoku Free (Genina)
This game is the best rated and most downloaded Sudoku game and indeed it is pretty interesting, compelling and easy to navigate. It has 4 levels, auto-save, auto-fill and erase, intelligent hints etc. The layout and overall look of the app is intuitive and smart. Great, addictive and fun to play.
Google Play Download Link: SUDOKU FREE
To be honest with you, I personally liked the design, UI and the colors of Sudoku Fun much more. It seems to me like they payed more attention to details than Sudoku Free. The background music is relaxing, the game is smooth, there are no lags, and all the standard features are here. Everything is user friendly, simple and neat and that is why Sudoku Fun is the best rated Sudoku app with 4.7 average rating.
Google Play Download Link: SUDOKU FUN
Sudoku Free (AI Factory)
I liked the interface and the graphics of Sudoku Free by AI Factory very much. Like the previous developers, they did pay a lot of attention on details. The game has over 1500 puzzles and 5 game levels. Some of the features include: statistic tracking, undo and hints. Another easy to navigate, interesting and challenging Sudoku game that you need to check out.
Google Play Download Link: SUDOKU FREE (AI FACTORY)
Sudoku Plus is less popular than the previous games. But, that can't take the quality of this Sudoku game, because it is simple, neat and fun game. The puzzle is big enough, the layout is user friendly and the whole design is minimalistic and clean. It is maybe the simplest of all games on this lists, so if you want basic Sudoku, with wide variety of puzzles, then this is the game for you.
Google Play Download Link: SUDOKU PLUS
Sudoku 10,000 Free
This game is the most customizable Sudoku game on the list and with most puzzles as well. There are all the standard features, 8 game levels, 6 input methods, highlighting of digits etc. I don't know why this game isn't so popular and more downloaded.
Google Play Download Link: SUDOKU 10,000 FREE
So that's it, if you have some quality Sudoku game that I've missed just post in the comments.