OK, so this is Android, but is harkens back to the glory days of Psion, classic Symbian, Communicators, the HTC 7 Pro(!), and much more. The Gemini was designed by the same guy who designed the Psion Series 5, back in 1996, so it's worth taking a look, at least. For my Phones Show, I've now reviewed the Gemini and I think many people will find my verdict of interest. It can run Android, Linux or Sailfish (currently), it can run at a wide variety of screen scalings, it has full travel keys and pretty modern phone internals. 

Worth a watch, hopefully. As usual with 1080p videos, maximise the playback window (if you can) or click on the YouTube logo to go through to the full thing:

As I said in my summary above:

In the meantime, if you, like me, felt your heart skip a beat when the Gemini unfolds and you see what’s inside, ready for action, then - however many caveats I just went through - this just might be the productivity booster you’ve been waiting for. It’s certainly the geekiest fun you’ll have in 2018.

This being posted on AAS, this is as close as you'll get in the modern world to the old Communicator functionality.

This being posted on AAWP, the HTC 7 Pro mentioned above was a very rare and niche device, but many Lumia owners will have come in via the Symbian and Nokia routes, so you'll be familiar with the idea of a QWERTY clamshell. Watch the video to see how well this works out, though note that the components (cameras, mics, speakers, DAC) on the Gemini aren't in the same class as in the hardware that Nokia used to produce in quantity.