These challenging original puzzles can all be solved with pure logic and are a great way to exercise your brain whenever you have a moment (or two) to spare. You'll feel like a genius when you're able to crack a puzzle and the solution falls into place! The first puzzle of this type appeared in the Japan Puzzle Championship 2006. When played with pencil and paper, these puzzles can be difficult to solve, which is probably why they are not widely known beyond the serious puzzling community. However, the Sumaddle app provides the essential element of interaction that transforms them into novel and intriguing brain teasers. This makes it possible for players of all skill levels to enjoy and appreciate the puzzles. Included in the app are more than 100 free puzzles, ranging from easy to very difficult. The built-in help is also completely free to use - this lets you fix mistakes and helps you to solve even the most difficult of puzzles, explaining the logical reasoning at every step. Yet even with so much free content, you won’t be bothered by ads - there are absolutely no ads!