001 Completed-Keeper-App
https://bit.ly/3qW2NxB

002 List-Docs
https://smartcontracts.org/docs/base-libraries/List.html

003 List-Docs
https://smartcontracts.org/docs/base-libraries/List.html

003 useEffect-Hook-Docs
https://reactjs.org/docs/hooks-effect.html

004 Example-Motoko-Playground
https://bit.ly/3uNGfQG