WordSudoku is an entirely, radical word/puzzle game that I invented. Summed up in one line, it's a crossword without any black boxes. You will have a 3x3 or 4x4 grid with certain letters fixed inside them. You will also have some other letters with which to fill the grid so that each row and each column forms a legitimate English word.
It's simple, yet engaging and logical. And if you're feeling up to it, you can play the 'Hard'-version, which contains no fixed tiles and every decision, then, is up to you.
And for the tech-inclined, this app was written in under 5 hours using Python, PyGame and the pgs4a library.
Note that this is the beta version. Bugs may be reported to the developer.