The method of encryption uses a symmetric key which is known to the two people exchanging the message. The sender of the message places the clear text message in the App and encrypts it with the key. The message is sent in its encrypted form to the other party via any communication program such as email, SMS, WhatsApp etc. The party receiving the encrypted message, pastes it into the Encrypt App and with the touch of one button decrypts the message back to its original clear text.
It can be used to encrypt any confidential information that you have such as logins and passwords.