If you want an app to scan and solve printed crosswords on your phone, Crossword Genius is a great option. The AI-powered app uses machine vision to scan printed crosswords and offers AI explanations and answers to cryptic clues. You can also import crosswords from the web for access to a huge library of puzzles. Available for iOS with an Android version in the works, it's good for beginners and experienced crossworders.
Another alternative is Google Lens, a built-in feature in several Google apps that uses your phone's camera to recognize text in real time. It's not specifically designed for crosswords, but Google Lens can recognize and translate text, making it a useful tool for scanning and solving other types of puzzles on the go. It works on multiple devices and apps, so you can get information without having to search for it manually.
For a more general-purpose document scanning app, iScanner has a lot of features, including document scanning with distortion correction, text recognition in multiple languages and document editing. It's not geared for crosswords, but iScanner's powerful scanning abilities and AI technology can be useful if you need to digitize other documents. It's available for Android and iOS.