@maxsidman Signal is a US-based non-profit organization. It’s operated by the Signal Foundation, which was founded in 2018 by Moxie Marlinspike (former CEO of Signal) and Brian Acton (co-founder of WhatsApp) based in Mountain View, California....I love Signal, and I use it but I don't know about including it just because...U.S.

There's some other options I haven't listed because I haven't tried or experienced. Threema for example. Will update as I go.