ChatSecure is a free and open source encrypted chat client for iOS
...ChatSecure only uses well-known open-source cryptographic libraries to keep your conversations private. Other apps may make claims about "military grade" security but, without publicly auditable source code and verifiable end-to-end encryption, you cannot be truly safe.
Crypt encryption and decryption is based on ASCII Table Shift.
Crypt is the developed based on the ASCII Table shift and it can customized based on the user requirements, right from the shifting order and the level of encryption or decryption. It can be integrated to any of the programming language with the custom build of the source code. It can secure from text file to binary code.