Is there an online tool to encrypt and decrypt messages, so that it is possible to use a general purpose chat service (such as Facebook Messenger or WhatsApp) with relative privacy?
For example I type in the tool
Hello how are you
Then the online encrypter tranlates the message to somehting mass-surveillence won't understand such as
Rhwmd hwi hen cyu
Then my correspondent receives the message and decodes it and retries the original message.
For now I found https://www.latoilescoute.net/decodeur/ but actually it only uses encodings without a password so they're very weak. But at least it's better than nothing.
The tool should ideally be extremely easy to use for me to discuss with people which are less skilled with computers or software than I am.