PGPro is a free, open-source iPhone application developed by Luca Naef. Designed for secure messaging and key management, PGPro allows users to encrypt and decrypt messages, as well as manage their OpenPGP keys. With a focus on simplicity and lightweight design, PGPro ensures that all data stays securely on the user's device.

One of the key features of PGPro is its ability to import keys from various sources such as files, clipboard, and the web. This includes support for Web Key Directory and OpenPGP Keyserver. Additionally, users can export all their keys to a GPG Keyring file for backup or sharing purposes. Individual keys can also be shared via the Share Sheet feature, making it easy to securely exchange keys with others.

For those concerned about the strength of their encryption, PGPro offers the option to generate new 3072-bit RSA keys. This ensures a high level of security for your messages and data. However, it's important to note that PGPro does have some limitations. It does not support sign-only or subkey-only keys, and symmetric encryption is not supported.

Overall, PGPro provides a user-friendly and reliable solution for secure messaging and key management on the iPhone. Its open-source nature and development in Switzerland further enhance its credibility and trustworthiness.