A live version of it is hosted here.
You can add it to your phone as an app, if you want to; just click menu / add to your homescreen.
The code you're seeing in the screenshot is here.
How to use it
Type the code on the textarea.
console.log( 1 );
First button clear the page and the cache with the code.
Second button downloads the code as script.js.
Third button runs the code.
As said above, your code is stored in cache, so you don't loose it.
Add a download button - to save the code as file.js.
Add a share button - to share via e-mail, whatsapp... a code solution with your friends (or classmates).
Do the above things without disturbing the minimalist design.