On 22 Oct 2020 at 05:12p, Charles Pierson pondered and said...
 
OK, so I've spoken about several ideas before in the abstract about  possibilities for BBS compatibile type apps for Android. 
At the time, I was operating under a semi-assumption that Android apps were written in Java. Since I don't know Java, and only found 1
program's source code in Java, I pretty much figured it was beyond my abilities. However, researching further, I've discovered that it is possible to write apps in other languages, such as C++, using something like Android Studio with some additional NDKs.
Indeed, you can write android applications in a variety of languages.
At this point, however, I cannot recommend languages like C++: they're
just too convoluted and too difficult to get the details right in.
Have you looked at Kotlin at all? That is the preferred Android language.
So my question is this, is there any difference in code going from one  OS/platform whatever you want to call it to another?
I suppose this depends on what, precisely, you mean?  Do you mean is
there difference in code you'd right for, say, Windows and code for Linux
and code for Android?  Again, the answer is "it depends".  Specifically,
it depends on how you use the features of those systems, and whether you
do so in such a way that the details are abstracted away from your program.
For many programs, this is fine; say, stuff that just does simple IO and computation.  But if you make use of the operating system for something
that's not strictly defined by the language you're using, then in general
the answer is "no."  Consider, for example, creating a new process.  On
the Unix family this is often done using `fork`, while on Windows there's
a system facility called (I think) `CreateProcess`.  You can write something that abstracts away the difference from the bulk of your code (and indeed,
you should do so as just a general software engineering hygiene principle!)
but at some point that difference does exist: it isn't turtles all the way down, at some point the turtle's got to stand on something.
--- Mystic BBS v1.12 A46 2020/08/26 (Windows/32)
 * Origin: Agency BBS | Dunedin, New Zealand | agency.bbs.nz (21:1/101)