GPG Suite is described as 'GPG for Mail is an open source plugin for Apple Mail. Encrypt, decrypt, sign and verify mails using OpenPGP with a few simple clicks. GPG Keychain' and is an app in the Security & Privacy category. There are more than 25 alternatives to GPG Suite for a variety of platforms, including Windows, Mac, Linux, Android and OpenPGP. The best alternative is GnuPG, which is both free and Open Source. Other great apps like GPG Suite are GPG4Win (Free, Open Source), AES Crypt (Free, Open Source), Encrypto (Free) and Kleopatra (Free, Open Source).
nCrypted Cloud is a Privacy, Security, and Collaboration solution that gives users full control over their personal and corporate Dropbox data. nCrypted Cloud adds client side encryption to your Dropbox existing data, and does not require you to migrate or move your files.