@DedicatedTiger, for ”print-based” apps, you can of course use the debugger, pdb.
For UI-driven apps this becomes a bit more challenging, especially on small phone screens.
I guess we can stdin/out from pdb, then use it to control the code execution in the background, but where to display it? @JonB’s work on overlays is an option, but would a semitransparent display of code be anything but confusing?