What's the best iOS app for improving vocabulary through daily puzzles?

Arrow Crosswords is an iOS app designed to make vocabulary building an enjoyable daily habit. It features a wide range of crossword puzzles that are updated regularly, ensuring users always have fresh content to explore. The app includes a built-in dictionary tool, allowing players to instantly look up definitions of unfamiliar words encountered during gameplay. This is particularly useful for students, language learners, or anyone aiming to expand their lexical knowledge during commutes or breaks. Users report that the puzzles strike a good balance between challenge and accessibility, helping them discover terms like 'ephemeral' or 'ubiquitous' in context. However, some reviews note that the high frequency of ads can interrupt the flow, though an in-app purchase option removes them. With features like progress tracking and themed puzzles, Arrow Crosswords encourages consistent practice, which is key to vocabulary retention. It's a solid choice for those seeking a playful yet educational approach to word skills.