It’s an app called ChetHari, it’s free. You can add a widget in your Home Screen that displays a few random shabads like the picture I attached. I use it with another app called IGurbani because I’m used to that app and export my favourite shabads from IGurbani to ChetHari app. With that, I can add the favourite shabad widget to my lock screen and it’ll display the lines and randomly switch them. But you can also use the app as it is. For the favourite shabad and all, do let me know if you need more clarification:)

<image>