Free version is so good I had to upgrade

Ive been playing this for a while. I have another free version on my phone, and it has two big drawbacks: 1) lately it is inundated with ads, and 2) if Im stuck, I can reveal the answer but I dont learn anything.

This version is great because if Im stuck, there are tutorials, which get more and more in-depth. For a while I didnt understand about the "fatal combination" or whatever its called -- what it is, there are some number patterns that would allow for two correct solutions. The pure Sudoku always has a solution and only one solution. So in addition to not having two of the same number in a row, column or rectangle, I also cant have a situation where theres more than one possibility. Im learning. (Slowly). The tutorials proceed slowly, so if I get it sooner, I can return to the game sooner.

NanaEllen about :) Sudoku +, v5.2.6