2023's _<I>PC-Phone_&nbsp;USB_&nbsp;Sync_</I> app, running on an Android-13 
_<A HREF="https://wikipedia.org/wiki/Samsung_Galaxy_Z_Fold_5">Fold5_</A>.

This portable content backup/sync program runs on Android phones and 
_<A HREF="https://quixotely.com/PC-Phone%20USB%20Sync/+screenshots/Android/Tablet-Android13/_thumbspage/tx-landscape-main.jpg.html">tablets_</A>, 
as well as Windows, macOS, and Linux 
_<A HREF="https://quixotely.com/PC-Phone%20USB%20Sync/+screenshots/macOS/_thumbspage/20-main-picks.png.html">PCs_</A>.  
It can be used to both backup folders and sync them 
between a mix of devices.  By using USB drives for 
propagating changes, it avoids the slowness and privacy 
issues inherent in clouds.

This app is the culmination of a five-year content-processing 
odyssey on Android and a decade-long sync saga in general.
It's largely the open-source 
_<A HREF="https://learning-python.com/mergeall.html">_<I>Mergeall_</I>_</A> 
system under the hood, with a new portable UI coded in 
_<A HREF="https://kivy.org/">Kivy_</A>
to support the Android app.  Products are built using 
_<A HREF="https://buildozer.readthedocs.io/en/latest/">Buildozer_</A>
for Android and 
_<A HREF="https://pyinstaller.org/en/stable/">PyInstaller_</A> 
for PCs.

On Android, it uses permissions available to standalone 
apps to regain access to USB drives and shared storage lost 
in Android 11.  On all platforms, it's coded entirely in
portable 
_<A HREF="https://learning-python.com/about-python.html">Python_</A>, 
and uses traditional POSIX file-path tools to process 
content—despite Android's self-defeating efforts to deprecate 
all such interoperable 
_<A HREF="https://learning-python.com/mergeall-android11-updates.html#asb4">things_</A>.

The Android app was initially paid, partly to fund visibility 
on the payola that is Play, and partly because free generally 
implies ad farms or junk on that platform.  The PC apps/executables 
are free, and there's a free trial Android app for test-drives.

Visit the app's 
_<A HREF="https://quixotely.com/PC-Phone USB Sync">website_</A>
for screenshots, videos, free downloads, and the full story, 
and keep your digital property safe from the many dark agendas out there.  

_<HR>
_<I>2024 update_</I>: this app was eventually made free on Android, too, 
per the "Why Free?" button in the news post on 
_<A HREF="https://quixotely.com/PC-Phone%20USB%20Sync/News.html#1.3.0">quixotely.com_</A>.
Please enjoy the app on all your devices, and help spread the 
word that storing personal digital property on clouds 
is inherently perilous and needlessly slow.