Tested working with Ubuntu 16.x & Linux Mint XFCE

PPA to add:
sudo add-apt-repository ppa:varlesh-l/indicator-kdeconnect

Install with:
sudo apt update && sudo apt install kdeconnect indicator-kdeconnect

Source:
https://websetnet.com/kde-connect-indicator-now-lets-send-sms-ubuntu-desktop/

Hope this helps!