Steve.
Thank you for all your help.
I have some friends working in LAS HERAS and i know the patagonian landscape and weather, but now i live in the center plains of Argentina, not the south 
For your help... I owe you some alfajores santafesinos (a candy) and a few beers from my province.
Well. I started this life as programmer and then i transform in Geologist, to return to a programmer-geologist kind of mix.
In the earth science many scholars doesn't like the OVER use of the technology, some are RUSTY... DUSTY.
But this are tools, for make a BETTER measurement, the human are impossible to replace, because we must make ASSUMPTIONS AND MAKE HYPOTHESIS OF THINGS HAPPENING TO THE EARTH (until now... maybe in a future other planets!!!), i am too optimistic.
Off couse i have my regular compass, i use the wulf net, and i take all the notes. But i think this tool, could be a DOUBLE CHECK SYSTEM. i Also think to use ----------->Differential GPS, for EXTRA-HYPER-MEGA-ULTRA PRECISION MEASUREMENT 
And that's the 2nd catch. I think i can connect with ESP32 or Raspberry pi Zero or Pico, with this GPS. (This things i have in mind).
The regular compass have some bad readings. But i have a good commercial phones with Military standard 810g. Well. I found them VERY GOOD for the use in the field. (even if the phone fall to the earth, the earth is damaged I also have in mind a phone with Iridium, for when i make my consulting.
Speaking...I also program for ZX Spectrum-Commodore 8bit computers, I have worked with sketchware (similar to AI2), and works well, i used Kodular with bad experiences, I am learning Python and microPython. I know a little of Java and Kotlin (little), but i am planning to solve it with time.
.
For ZX i even used Many kind of Basic, Prolog, Lisp, Forth, Machine code and Assembler. (But now i am too old for do that ASM i mean), and i use some engines like AGD MPAGD, SEUD and others to develop (games for 8 bit computers as a hobby).
. When i was in the University i had worked with R, but i didn't count. It's too academical to use in daily life. And with all other languages, all i can use it for fun too. (R don't)
I have the app GPS-compass-dbase working. Only need the stereo plotting part, but seems i must do it in parts. 1 for taking the data and 1 for the stereo plotting.
I used the mplsetereonet pack and its EASY for plot some points, but make a dbase, store, an register is another thing. I never use it for make a complex program. And less port to android. (i think i will go in that way, but with time, not now)
.
About this post...
.
I read it some months-weeks ago, because i want to make a (SIMILAR) app, but for Geochemestry. FOR SOIL, we use the USGS chart, with some variants. But we use some European classifications too, and sometimes is a mess. For color we use an French classification with Argentinian variants.
The same happens to me, with Gauss Kruger notation for coordenates.
I found a user who have an extension.... BUT GAUSS KRUGER is like a way of measurement, NOT A SINGLE UNIQUE WAY.
Example of that, Russia have a lot of bands and use SK42, we use WGS84 and Argentina have 7 bands (i live in the 5th).
I look the extension, was REALLY EASY TO USE, but the data was bad for ME, because there is NOT AN STANDARD, will could be used but for other countries. (i asked to the developer to add MORE INFO BECAUSE THIS COULD BE A PROBLEM, BECAUSE IF YOU DO NOT CHECK, ALL THE DATA WILL BE BAD). Again. The extension works GREAT, but show bad data, data for use in other place, because the coordinates aren't what must be. I triple check, and i know the coord, because i recorded for ME, and there were of my town monolith for gauss kruger national system.
.
My app for soil, recognize (Color), not size of grain, and this app could and seems to get tuned for, but also is interest.
.
I was making a sketch board (like the paint pot) but different, for sketching maps in the field.
BUT, i need a menu for sprites (to add the different references), for mapping. I also doesn't find anything like this. I want to drag sprites and get into a canvas. like traces (reference graph) for a handwrited map... like a treasure map? you can use some sprites to show, where is the Treasure (fault?, kind of rock, train, route, dan, etc ), with different kind of colors for different kind of rocks.
Well. I am in a pause, because i am watching if i can add this menu with sprites for use in the map app.
.
Now i am developing an app for stratigraphy.
Like a dbase. And then get the log with all of the strata inside.
This also, is didn't find any app for academical and or COMMERCIAL TOO.
Maybe for commercial there are... I didn't find it.
.
Well Steve. Thanks a lot for all the references you make, they point me in a way to continue reading and learning.
And if you come to Argentina, write me and if i can, i will give the cervezas and alfajores i own you!.
.
Thanks again.
Germán.