An alternative to KDE Connect is Pushbullet. While the free version has some limitations and it doesn't offer all the features available with KDE Connect, it does provide options to send files up to 25MB, send messages from your desktop (limited to 100/month in the free version, and a storage cap of 2GB) and most importantly, it can mirror your phone's notifications on the desktop.

Note that Pushbullet requires both the Android device and desktop to be connected to the Internet, but they don't have to be in the same network.

Pushbullet is a service that lets you easily send files, links, notes, list and more to your Android or iOS device from your desktop or the other way around. The tool can also be used share the clipboard between your desktop and mobile device (feature called "Universal copy & paste"), mirror Android notifications on your desktop and more.

Universal Copy & Paste allows you to copy a link or some text from a device and paste it on another device. For now, this feature only works one way with Pushbullet Indicator: you can copy a link or some text on your Android device and then paste it on your Ubuntu desktop, but it doesn't work the other way around, because the Pushbullet API doesn't allow this for now. 

For those not familiar with Pushbullet, this is a service that lets you easily send files, links, notes, lists, etc. from your iOS or Android device to your desktop or the other way around. It can be used via Chrome / Firefox extensions and for Windows there's also a desktop app. Because there was no native Linux app, Lorenzo from Atareao.es created an Ubuntu AppIndicator (and a Nautilus extension as a companion for the AppIndicator) to easily use Pushbullet in Ubuntu.