Evil Twin

The Evil Twin app is an experimental motivation app that aims to change the habits of an individual through punishment in a humorous way.

  • Year


  • Tags

    Interaction · GUI

  • Duration

    1 week

  • Links

    CIID website


By tracking your credit card and geolocation data, the app gathers insights about your behaviour. You could, for example, set a goal to drink less coffee. Then, every time the Evil Twin learns about you paying for a coffee, it will punish you by locking your Facebook account or similar disciplinary actions. You can read more about the initial concept at the CIID website.


Starting with this idea, the last part of the project was dedicated to the exploration of the actual interface. In this version, the Evil Twin app uses a conversational interface with a few additions. In conjunction with the usual predefined answers in conversational interfaces (ie. Quartz app) the app changes its speech bubble style so that you can use direct input or sliders. Various user tests helped to define the humorous tonality of the alter ego.

Usually, conversational interfaces can become frustrating due to the fact that you can only select one answer. To provide a smoother user experience, you can undo certain answers in this prototype.