Jeff Widderich had the idea for Str8ts in 2008. Together with Andrew Stuart, he developed a new puzzle that is a successful successor to Sudoku. It is a puzzle where you have to enter the numbers 1 to 9 in the fields, where each digit may occur only once per line and column.
With the app you can daily download new puzzles and solve them for free. There are puzzles in different difficulty levels, so that everyone will find something for their level of knowledge. If you can not find a solution, the integrated solver helps to find the next steps. The integrated solver is able to solve even the most extreme str8ts puzzles with a backtracking algorithm. So far, we've only found two puzzles where the one-step backtracking algorithm did not find a solution and needed support from the user.
As a further function, you can even enter puzzles, which are available for example in printed form, by hand. An import via a text format is also possible.
We thank Jeff Widderich and Andrew Stuart, who gave us permission to use the name "Str8ts". A highlight, of course, is the link from Andrew, through which he daily provides us with new puzzles for the app.