Let's vote for suggestions and bugs

[CyberAngel]

The next Prime should have pogo pins and rails to attach a module
(and akeyboard overlay holders à la HP-41,71).

A student can buy a phone module and
use the calculator as
A] A superior and wonderful feature phone using a cheap module. This module is extremely affordable.
Basically it holds double antennas, dual SIMs and a μSD card plus a chip to handle calls.
B] Buy the more expensive module and get a very poor Android phone, but also Google play. Ask your operator for more details.
C] Custom modules pop up everywhere since the HP expansion port interfacing data is free.
D] Deluxe phone module available in the US from AT&T only. You get it for free when you buy a phone plan.
E] ...
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Plan [B] put the dual antennas in the calculator frame
and lead the signal to the 3x3 pogo grid
Note: Doogee already sells phones that can get extension modules. S90 Pro is extremely versatile. It even offers a walkie-talkie module!