Out of curiosity, is something like a Raspberry Pi Zero an option in terms of availability and having the equipment lying around to make it work (i.e. SD card, usb plug, etc.)?
You should consider reaching out to the Raspberry Pi Foundation and explaining the situation. It is a registered charity and may have a program for distributing kits (and covering the associated costs) to areas or individuals who do not have easy access to hardware.
It's probably a step-up from just using a phone or phablet but with a Raspi you'd still need (compatible) monitors. No idea what the availability and markup is for these though reliable electricity might be another issue for remote regions.
Here in Haiti, it’s the electricity issue. If you’re lucky you can get electricity for 6 hour a day. In the middle of the night. That’s why people prefer portable stuff, because you can easily charge them somewhere else (in my native town, there are people that have setup charging stations with batteries and inverter).
You should consider reaching out to the Raspberry Pi Foundation and explaining the situation. It is a registered charity and may have a program for distributing kits (and covering the associated costs) to areas or individuals who do not have easy access to hardware.