Earlier this year I played the previous game Go to Gold and positively loved it. In this game, the first 18 levels or so are free. After that it costs money - I forgot how much I paid. But it's worth it. These puzzles are so well crafted. I've done probably several thousand sokoban puzzles over the years. These are simply fantastic. At the moment I've done about 59of the 72 puzzles.
What's new: One type of block can only get pushed either vertically or horizontally, not in both directions.
Timur Nigmetzianov is the author and he's hit a home run.
Other Sokoban Games:
Go to Gold - superb
Push Box Sokoban
Boxed In - loved this.
BoxWorld - awesome. I still remember struggling through levels 26 and 35 for days.
Paper & Light
Square Push Square
Jewel Keeper - the only puzzle app that needlessly inserted a beautiful woman.