Not Evil Sudoku 4+‎

Built natively for iPhone and iPad with the sole aim of providing users with a joyful sudoku-solving experience. Never played before? Move by Move validation in Settings can tell you whether your moves are correct as you make them.

Features:
- Fully offline
- Ad-free
- Real-time move checking
- Timer: Track your sudoku-solving speed. The timer can be hidden in Settings if time pressure isn't your thing.
- Difficulty Modes: Easy, Medium, Hard
- Haptic Feedback
- Notes: Users can keep track of all the candidates for a cell with two modes:
- the default which supports up to 4 notes which is ideal for easy and medium puzzles
- the expanded version which supports up to 9 notes (Settings → More Settings → Expanded Notes)
- Auto-clear Notes: When a number is placed, all instances of that number in notes in the same row, column and grid are cleared.
- Undo: Take back the last action.
- Streak: Number of consecutive days in which you’ve solved a puzzle.
- Best Time: The shortest amount of time it has taken you to solve a puzzle (separate for easy, medium and hard)
- Charts (Pro):
- Track your solve speed over time for each of the difficulties
- See how many games of each difficulty you played
- Highlighter: When the user taps a number, the app highlights all the places where that number appears, making solving much faster.
- Game Controls: Start over or start a new game at any time
- Daily Sudoku Reminder: Sends a notification at the time the user chooses. For those who like playing a daily puzzle and don’t want to lose their streak.
- Display Modes: Supports light and dark modes as well as switching between them within the app.
- Themes: Switch up the app theme to freshen up the experience. Some colors require Pro.
- Fun Alternate App icons (Pro).
- Unlimited puzzles (Pro)

Users can play a daily sudoku game for free while leveraging all the powerful features of the app. Unlimited games can be unlocked with a small one-time purchase (Pro). Pro supports family sharing.