Pretty good but needs improvement – Killer Sudoku + Review

I tried one of the puzzles and it is a little confusing to start with as there is no obvious note taking. I realized that I just keep putting in numbers and that's how it does it. But then when I figure out which number should be there, I have to go through the ordeal of deleting every number that I don't need. I would also like the addition of a calculator and the option to add numbers into multiple squares at once. It would make game play much faster and less frustrating. The puzzles seem pretty good though.
Review by Splamy91 on Killer Sudoku +.