The first thing I like to install is the KDE Network management widget. It is not present in Debian KDE by default.

package: plasma-widget-networkmanagement

Another thing noticed is the odd message “Networking interface unmanaged” instead of setting and displaying a name

Fix:

sudo kate /etc/NetworkManager/NetworkManager.conf

The file probably contains:

[ifupdown]
managed=false[/code]
Change false to true and restart Network Management
/etc/init.d/network-manager restart[/code]
.
12 hour time:
Open KDE Country. region, Language applet:

Times & Dates>Time format>

Change to pH:MM:SS AMPM

 
Other widgets to add:
System tray (Contains volume, USB notifier etc)

Task manager (this is the horizontal tab of apps)

 
Favorite apps:
Shutter (screenshot manager)

Gimp (Image manipulator)

mc (file manager)

filezilla (ftp client)

gparted and parted

emacs

You can install all these at a go:
sudo apt-get install shutter mc filezilla gimp libx11-dev libxtst-dev emacs
libx11-dev and libxtst-dev are the dependencies of ksuperkey (along with make and build-essential).
Video thumbnails in Dolphin:
Install mplayerthumbs.
sudo apt-get install mplayerthumbs
Now enable previews in Dolphin settings>General>Previews>Video files(mplayerthumbs)
Addon scripts
Ksuperkey (Allows mapping of Win (superkey) key to the KDE app launcher, and simultaneously use  shortcuts with the key too. Follow these instructions.
 
Joel G Mathew
Joel G Mathew, known in tech circles by the pseudonym Droidzone, is an opensource and programming enthusiast.
He is a full stack developer, whose favorite languages are currently Python and Vue.js. He is also fluent in Javascript, Flutter/Dart, Perl, PHP, SQL, C and bash shell scripting. He loves Linux, and can often be found tinkering with linux kernel code, and source code for GNU applications. He used to be an active developer on XDA forums, and his tinkered ROMS used to be very popular in the early 2000s.
His favorite pastime is grappling with GNU compilers, discovering newer Linux secrets, writing scripts, hacking roms, and programs (nothing illegal), reading, blogging. and testing out the latest gadgets.
When away from the tech world, Dr Joel G. Mathew is a practising ENT Surgeon, busy with surgeries and clinical practise.