Create a '.desktop' shortcut for 'Show Applications' on Ubuntu 18.04

First install xdotool by running the following command in Terminal

sudo apt install xdotool

The key combination Super+A shows the 'Show Applications' screen. The following command will simulate this specific combination

xdotool key super+a

So create a simple .desktop launcher and use the command above for the Exec= entry.

Although the answer above is the accepted and will certainly work if you use the xorg display server, following command directly "commands" Gnome Shell to show the applications overview.

dbus-send --session --type=method_call --dest=org.gnome.Shell /org/gnome/Shell org.gnome.Shell.Eval string:'Main.overview.show(); if (! Main.overview.viewSelector._showAppsButton.checked) {Main.overview.viewSelector._showAppsButton.checked = true;} else {Main.overview.hide();};'

So create a simple .desktop launcher and use the command above for the Exec = entry.

Whereas xdotool may not work reliably on Wayland, this approach will also work on Wayland without issues.

I actually created a lightweight deb installer to do this, check out my repo here https://github.com/milan102/Ubuntu-Launchpad

The installation instructions are in the github README. The program is a simple shell script that invokes the keyboard shortcut for showing applications (Super + A)