App Inventor 2 Tricks and Tutorials

https://appinventor2.droidim.com/2019/04/app-inventor-2-how-to-use-clock-component-as-countdown

https://appinventor2.droidim.com/2019/04/how-to-store-user-hightscores-with-app-inventor-2

Original https://appinventor2.droidim.com/2019/04/how-to-make-a-leaderboard-in-app-inventor-2-with-listviews