The next two screenshots show two of the Python programs I 
started working on after the LP5E book project: a personal
calendar/journal GUI and a content sync/backup system.
This page's image captures 
_<A HREF="https://learning-python.com/frigcal.html">_<I>Frigcal_</I>_</A>
on Windows.

Both use tkinter for their GUIs; were ported to work on macOS, 
Linux, and Windows (and later, 
_<A HREF="2019%20PyAndroid%201.jpg.html">Android_</A>); and were shipped
as source code, macOS app, and Windows and Linux executables.  
After decades of teaching the tools and techniques behind these,
it was nice to be able to apply them to something useful.
See this site's programs 
_<A HREF="https://learning-python.com/programs.html">page_</A> 
for more links and info.