Enigma can three touch to encrypt the text.
Enigma is also in the App Store for iOS and support other platforms (see Enigma menu).

Agree with the person about Your "Key" encryption (for example, the number "563"), and he will be able to decrypt Your message.

Features:

* as the encryption key, you can specify the date and time;
* the text can be any characters including emoticons.
* the length of the cipher does not match the length of the encrypted message;
* without special training and tools to break the encryption almost impossible;
* the resulting cipher is encrypted again.