Description: SUDOKU with UNLIMITED grids at ANY TIME:? UNLIMITED: MILLIONS of grids.? ANY TIME: on or offline.? CHALLENGING: 6 difficulty levels ranging from "easy" to "diabolical."SUDOKU with NO DISTRACTIONS:? FAST: no lengthy intros or slow animations.? FRIENDLY: big buttons avoid fat-fingering.? NON-INTRUSIVE: plays your iPOD MUSIC and nothing else.SUDOKU on ALL your DEVICES:? UNIVERSAL: iPad, iPhone, and iPod touch.? RETINA: native resolution on all screens.SUDOKU with all the NUTS and BOLTS:? UNDO / REDO.? 10 CONCURRENT GRIDS.? AUTOMATIC and MANUAL NOTES.? CONFLICT and ERROR HIGHLIGHTING.? CUSTOMIZABLE input and display settings.+ Sudoku is featured in the WIRED MAGAZINE APP GUIDE.Enjoy,The friendly team at mindthefrog :)