This app is an SMS app, and SMS is highly insecure by its nature. There is no way to encrypt or protect your conversations as they go between you and your contacts.
For storing your messages in the cloud, along with SSL for the requests, we use strong, end-to-end encryption techniques to ensure your data is kept secure and no one but you can access it.
This means that on our servers, your messages are encrypted using your password and even we cannot see what they contain. The only way to decrypt them is with your password within one of our apps.