Sudoku - Classic Numbers Game is a free iPhone app developed by 帅 李. This lifestyle app offers a classic Sudoku experience with thousands of well-formed, totally free puzzles. Whether you're a beginner looking to challenge your brain or an expert seeking a real workout, Sudoku has various difficulty levels to cater to your skill level.

The app features a beautifully recreated classic Sudoku design on your phone, allowing you to play the game with ease. You can use the pencil feature to make notes right on the puzzle, making it convenient for keeping track of possible numbers. Additionally, the app offers a highlight duplicates feature to help you solve the puzzle more efficiently.

Sudoku also provides customization options, allowing you to play the game your way. You can challenge yourself by limiting your mistakes to three or use hints to navigate through difficult puzzles. With four difficulty levels - Easy, Medium, Hard, and Expert - you can choose the level that suits your preference.

Please note that the app offers a premium VIP membership with a weekly subscription. This subscription unlocks all pictures and removes advertisements after a 3-day free trial. The app's privacy policy and terms of use can be found on the developer's website.

Overall, Sudoku - Classic Numbers Game is a feature-rich app that provides a satisfying Sudoku experience for players of all skill levels. Enjoy the challenge and have fun solving puzzles!