Grid Square Locator

100%

I put together a list of open source CAD software a couple of years ago, but none of the options are quite there yet.

This was how I did it, or at least what worked for me. https://www.n9drb.com/notes/#ADSB%20feeding

There's https://scholar.archive.org/

I wonder if Delta Chat would work for you.

Sad end of an era. My mother has been using the DVD service from pretty early on. Her internet isn't consistently fast enough to stream.