Updated: January 14, 2022
If you use the Plasma desktop on your Linux, as you should, and you also happen to have an Android phone, then the most convenient way to pair the two and share data and whatnot is through the use of KDE Connect. This is a built-in application available in all the modern releases of the Plasma desktop, and it lets you easily pair and control your phones.
I've tested the solution several times in the past, including an early release for Windows, and overall, the results were quite decent. Now, recently, I encountered a real usability problem as part of my Slimbook Pro adventures. For some odd reason, the computer wouldn't mount the Nokia 5.3 phone using the MTP protocol, which corresponds to the "File Transfer" option when you connect an Android device via USB. No such problem with any other Android device, including an almost identical Nokia 5.4. So I decided to power on KDE Connect, and thus, this little review was born.
KDE Connect in action
To get started, I installed the namesake app from the Play Store on the Nokia. As soon as I launched the app, it identified the Slimbook on the network, and I was able to request pairing. Worked fine. Then, I noticed that I couldn't do any file transfer or data browsing, because the KDE Connect app didn't have the permission to access any of the folders on the phone.
This is where things get really nice. Rather than asking for a blanket file access, KDE Connect lets you specify granular access to only certain folders, one or more. For example, you can have separate access for the DCIM folder with your camera photos, and a separate one for the Screenshots. Lovely Jubbly.
Fine control everywhere
But that's not all. Now, on your desktop, you can configure KDE Connect to do all sorts of things, in the typical ultra-flexible KDE fashion. The tool has lots of plugins, some of which can be further tweaked to your liking. The list of things that KDE Connect can do is long - clipboard sharing (both ways), multimedia control, media playback during calls, notifications, and then some.
For obvious security reasons, not all of these features will work unless you also grant the necessary permissions on your phone. Storage locations is just one example. SMS, remote keypresses, mouse use, notification sync, all of these require manual intervention. Then, you can also tweak the app notifications. For instance, I don't like the persistent indicator (next to the clock), so I have it disabled.
Fun goes both ways!
At the same time, you can also use your phone as a remote control for various activities on your Linux machine. Remote input, slideshow, file sending. Very convenient. Best of all, it works without a hitch. The visual styling of the app has also improved immensely. I remember some of the menus and available functions being rather crude, but that's no longer the case. KDE Connect feels rather polished. Very cool.
I was able to advance slides in LibreOffice, play music (and fiddle with the volume) in VLC, as well as move the mouse cursor on the Slimbook's desktop. I also sent files, which landed in the Downloads folder on the Linux machine by default. Lastly, as mentioned earlier, to have the desktop actually use the mouse cursor and control the phone, you need to give the right permissions under the Accessibility settings. But all in all, everything was peachy.
In addition to the Nokia 5.3 device, I tried a bunch of other Android phones. They all worked and behaved spotlessly. The functionality has really advanced a lot in the past couple of years, and I'm really pleased. KDE Connect is perhaps the killer app that Linux's always tried to have, and never managed to do. It has more than one million installs in the Play Store, so that's a rather respectable number.
Beyond raw numbers, the KDE Connect software + phone app really deliver. The pairing is simple yet secure. Adding storage locations comes with a great deal of flexibility (hence additional security, too). You can do fancy party tricks with the music, mouse and slideshow control. You can sync notifications, send data, even share the clipboard. All of this as a seamless, integral part of your Linux desktop, or if you fancy, your Windows box, too. What more could you ask for? Necessity brought me here, in a way. I came looking for copper, but I found gold.