A Question about Starting a Personal Projects

Hey guys,

As a newly grad software engineer with nearly 1 year experience i really would like to start on a personal project for self development, but i dont want to create something thats useless.

Do you guys think for a mobile app or a website (i dont know whatever) to become successful it should be creative, never thought before idea? I am really struggling with this idea lately and i am looking forward to hear your guys perspective on this topic.

Edit: sorry for my english