That's all Mahjong Master is: it's a classic game of Mahjong, no more and no less. It doesn't try to do funky things with new mechanics or give you points to spend or upgrade. All it does is present Mahjong, with calm music and a calm background. It's the sort of game that ordinarily would get no attention, which is exactly why I'm giving it some.
You have your choice of twelve layouts, beginning with the classic turtle, of course (which I always thought was a wicker basket when I was a kid). You also can choose between four kinds of tiles, and you can shuffle and take hints. Selectable tiles are highlighted, and immoveable tiles are dimmed. The best feature, of course, is being able to turn off the sound effects and music (as nice as they are) so you can listen to your own.
You also get to see how many tiles and matches you have left, which is especially useful to know when it's the appropriate time to shuffle.
Technically speaking, the matches number is slightly off, if you have a triple or quadruple match (having three matching tiles out gives three possible matches, but it reads as two, and likewise all four tiles out means six matches, but it reads as three). But that's the only bug in the whole thing.
Sit back, relax, unwind. Play Mahjong Master.