It's the default SMS application on Pixel devices.

You should check out the OpenNic project, which is an organization that has already attempted what you're describing.

https://www.opennic.org/

I swear - there used to be a segment on CBC kids where children would submit short films they had made. The mascot was an electric wall outlet; I have not been able to find anyone else who remembers this but it was definitely real because I have a number of home movies I wanted to submit to it.