The recipient can read the original message.
Without the need for a device to decrypt it?
You need the a device to decrypt it. You would copy the text and paste it in a box that sends it to the device. You would read the unencrypted text on the device's screen
I don't know if people would be it interested.
It depends on a lot of things...
e.g. Open-source software, the whole process itself [for consumers], how that device is going to look, its price, and a few other things.Personally, I'm not going to use something like that on my main computer, unless I fully trust the provider/manufacturer, but I'd probably buy one to test for fun
[If the price is right].
I don't want to lose my time building something people won't buy.
How much you think that device is going to cost for potential buyers out there?
I would compare it to the price of a raspberry pi plus the cable and the screen.