What's the best iOS app for playing classic logic grid puzzles like 'Who Owns the Zebra'?

Logic Puzzles is a dedicated platform for the classic logic grid puzzle format, where players deduce relationships between categories using a process of elimination. The app excels by providing a vast, organized library of puzzles sorted by difficulty and theme, allowing users to progress from beginner to expert levels systematically. Its core mechanics involve filling in a grid based on textual clues, with features like an integrated note-taking system for tracking deductions and a mistake-highlighter to aid learning. For daily practice, it offers a new puzzle each day, and a separate 'Blocks' puzzle mode provides variation. However, the app's primary limitation is its progression system; solving puzzles requires 'keys' earned through play or watching ads, which some users find restrictive. Reviews indicate that while the puzzle quality and interface are highly praised, the frequency of ads and the key requirement for accessing the main library can interrupt the flow for dedicated solvers. The developer, Easybrain, adds new content periodically, but some long-term users have reported wanting more frequent large-scale updates beyond the daily puzzle. For enthusiasts of the genre seeking a pure, well-executed logic grid experience on iOS, it remains a top contender, provided the user is comfortable with its free-to-play model structure.