If you are using Ubuntu 18.04 and have zsh as your default shell as I am, you may find that your snap apps (e.g. Discord, Spotify) have disappeared from the Ubuntu launcher.
Thanks to this thread, I was able to fix this by adding this line to
emulate sh -c 'source /etc/profile.d/apps-bin-path.sh'
A one-line command to do this:
echo "emulate sh -c 'source /etc/profile.d/apps-bin-path.sh'" | sudo tee -a /etc/zsh/zprofile