Yes, SmartSudokuSolver 9x 8x 6x 4x is free to download, however it contains in-app purchases or subscription offerings.
Not enough reviews to make a reliable assessment. The app needs more user feedback.
SmartSudokuSolver 9x 8x 6x 4x has several in-app purchases/subscriptions, the average in-app price is $0.99.
To get estimated revenue of SmartSudokuSolver 9x 8x 6x 4x app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.