I first became interested in SuDoku many years ago, when I discovered Japanese news-agents (whatever they are called) were selling compilations of puzzles much as we can buy books of crosswords at a railway station. For me, SuDoku offered a challenge in application of logic, and I wrote a set of algorithms to solve these puzzles - really just an exercise in programming.
Today you will find few useful English-language references to SuDoku on a web-search, and I have found none which explain anything other than rudimentary guidance on solving the grid. SuDoku Master sets out to fill this gap. Among its features are the ability to watch a grid solved step-by-step, with an on-screen explanation of each of the nine rules of logic as they are applied. In Demonstration mode it will solve over a hundred grids as you watch over a cup of (Japanese) tea. Simple grids are solved in less than a second - really difficult ones can take longer. You can print out grids and solutions, as well as blank grids for practising on paper.