For sure you can add more features to your project to impress the judges, so go on if you have some ideas :)
About last year 24hrs challenge: the theme was technology and education. In the 24 hrs the point was an educative application for childs between 4 and 6 years old that can help them to learn quickly something(math, write, drawing etc).We created something to learn childs to draw.
2 year ago the theme was technology and health and the 24 hrs theme was to create an application for using in critical situations in medicine. We created a great interface for blood transfusions.
If you have more questions, ask me :)