A Cryptoswift developer primarily works on creating and maintaining security software for iOS applications. They use the Cryptoswift library, a powerful tool for cryptographic operations in Swift programming language. Their tasks include incorporating data encryption and decryption, hashing, and secure random number generation into applications. They ensure the safety of digital information from unauthorized access, protecting sensitive user data like passwords or financial information. They also troubleshoot and resolve any security issues that may arise, constantly update their knowledge of new security threats, and implement appropriate countermeasures to maintain the highest level of security in their applications.