This app shows conditionals, functions, loops, arrays, objects, event listeners, creating DOM objects and appending to them (both via .createElement and using .innerHTML).
The app is a show of Harry Potter character cards, with sliders to shape their personality in order for the hat (the button) to sort the character, choosing which house they are supposed to go to.
The colour of the card's background changes when the button is clicked, indicating the house the character is a part of.
The app also is responsive, styled to fit various screen sizes.