Three puzzles, one app
A sudoku, a cryptogram and a codebreaker, made properly. No adverts interrupting you, no account to create, and nothing collected about you. It is free because it is not selling anything, including you.
Nine by nine, three difficulties. Every board is checked before you see it: a clue is only removed while exactly one solution remains, so a puzzle can never have two answers and can never tell you that a correct grid is wrong.
A quote hidden behind a substitution cipher. Every letter stands for a different one, consistently, and you break it by deduction. Letter counts are shown, because frequency analysis is the oldest trick in codebreaking.
A hidden code of four or five letters. Each guess tells you how many were right in the right place and how many were right in the wrong place, never which. Letters you have proved impossible are dimmed for you.
Because the alternative is worse. Free puzzle apps are usually paid for with adverts, and the adverts are why they look the way they do: the layout is built around the ad unit rather than the puzzle. Enigma has no adverts to design around, so the puzzle gets the whole screen.
It is made by Pixel and Shovel, a small studio in Sussex, as a piece of work we are happy to be judged on.