OpenPGP Manager

OpenPGP Manager is an encryption client for Android, capable of:

* Create/import/export/publish/search PGP keys
* Send/receive encrypted mail with Gmail
* PGP encryption/decryption of mail & files
* Thunderbird integration (via gnupg + Enigmail plugin)
* Password-based encryption/decryption (AES-256, 3DES, RC2...)
* Sign & verify files and emails
* Subkeys viewing and editing
* Biometric words
* Key armoring

Public-key cryptography is in most cases the best choice to protect your mail and communications from being intercepted and/or sniffed by governments, NSA's PRISM surveillance program and such.