When installing an Ubuntu based distribution (KDE Neon in my case), I always add the following extra package archives. This list is a reminder for me, but you might find it useful.
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:lyzardking/ubuntu-make
sudo add-apt-repository ppa:seafile/seafile-client
sudo add-apt-repository ppa:libreoffice/ppa
sudo add-apt-repository ppa:phoerious/keepassxc
sudo add-apt-repository ppa:webupd8team/atom
Update the package index
sudo apt-get update
Install the packages
sudo apt-get install -y seafile-gui libreoffice keepassxc ubuntu-make atom
Install IntelliJ IDEA
umake ide idea-ultimate
And then I manually download and install Signal, Slack and Spotify :)