KDE Connect is a Linux app allowing to share things between your phone and a Linux desktop:
Sharing copy/paste buffer;
Pushing files directly to your PC;
Showing SMS and other notifications on Linux desktop;
Controlling music playing on Linux desktop from your phone (works with browser media if Plasma extension is installed: Firefox, Chrome)
Showing who’s calling to you on your desktop, even if your phone lies God knows where in your apartment.
Some other functions (that I don’t use :-)
AFAIK it is similar to the integration that Apple provides, but much, much cheaper. I use Raspberry Pi as my desktop, an upgrade that cost me 150 USD, and any Android phone can be used for that. I use Kubuntu, KDE Connect is “native” to it, but you can use it with Raspberry Pi OS (Raspbian, ARMbian), as well as with Xubuntu or other desktop configurations.
How to install it
Get KDE Connect from your distro’s repository. In case of Ubuntu derivatives or Debian, run:
sudo apt install kdeconnect
Also, you need the pairing app for your Android phone - iOS is not supported now due to some issues (one of them GPL not being compatible to App Store license).
Then, run KDE Connect on your Linux desktop and Android phone and pair them—you must have them both connected to the same Wi-Fi network.
Is it safe?
It stays LAN, encrypts your phone and desktop communication, and it is an open source app that allows anyone with enough knowledge to audit how safe it is. However, as with any apps that you use, you are the person who should control your personal information safety, so checking news about safety of apps that you use is what I’d recommend.
Other platforms
iOS app for pairing is not available yet, but if you want to pair your Android phone to your Mac or Windows desktop, I’d encourage you try it. Binaries available on the official site, and you can build them from source code if you want to.
I managed to install KDE on my pi, and most things work, EXCEPT notifications/ pinging the Pi from my android. Any idea what might be wrong?