AES Encryption add-on (app) for sms client (android)

We are searching for someone who is able to create an app with symmetric encryption system using known cipher AES 256 CBC. Many apps are builded in a way separated from sms client, so it's working on it's own, so after all it will give to user an option to encrypt text and then share over selected app. Here is an example: [login to view URL] Note: We don't want app like this one, but if it's possible to build something like add-on for sms client, or simple sms client with encryption option. More details on private.