The Windows app has an option in the Preferences menu to auto-start the app whenever you log in to your account on the computer. When enabled, Pulse will start itself and open the window automatically. So you'll have access to notifications without having to remember to start the app yourself.
For MacOS machines, you can right-click on the dock icon and select the Open at Login option. Again, this is a build-in to MacOS.
Linux machines do not currently provide an API for automatically starting the app.
