>there are Blackberry-style client devices which don't require an app at all, and all the actual firmware is open source (MIT).

Worth noting that the Blackberry-style devices are also closed source and the hardware and software is way worse than Blackberry was 22 years ago.[0]

[0] https://mtlynch.io/first-impressions-of-meshcore/#this-is-no...

Good to know - I've only used the companion radios. That firmware and the repeater firmware is open, which is what seems important to me.

I wasn't expecting the T-Deck to be anything more sophisticated than a walkie-talkie for SMS, but it's a bummer than the UI code isn't open.