On Saturday, September 16, 2017 at 8:13:44 AM UTC+12, Soartech wrote:
Why not run a yotaphone? E-ink on one side...

Yes, and LCD on the other. I tried to get my Nook to run TopHat and have had zero luck. It is not possible withouot taking it apart and doing some soldering.Even then you have to have a serial output GPS. Newer USB output GPS will not work. I was lucky enough to test fly a Yodaphone (not sure about the spelling) and it worked well. However last time I searched for them online they were not sold in the USA. Probably because
they are made in Russia... might include spyware at no extra charge :-)

I've been using an Android based e-reader for a few seasons now. XCSoar runs on it nicely, standard install, nothing fancy. Just upgraded to a faster display that reduces the flashing on refresh.

Using a Boox e-reader from Onyx. 6 inch e-ink display. I got mine from Banggood.com.
Connecting to Flarm using an ioio adapter and the UART interface kit from Soartronics.

Works great and very reliable.