Smart Egg Timer

Tamago is a smart egg timer that helps people boil the perfect eggs. It works by adjusting cooking time based on user’s preference. It consists of a portable device that monitors the water temperature, and a companion mobile app.

My role

I was the UX and UI designer, created prototypes of a mobile companion app, 3D model, and demostration video . This was a 2-week project in collobration with Kosuke Shiraishi.

Secondary Research

We started with online research and discussed our findings on how people usually cook boiled eggs and their pain points. One big problem was the softness of cooked eggs varies greatly even if a user cooks with a kitchen timer. In order to boil a perfect egg, cooking time needs to be determined by water temperature and weight of eggs. After exploring several possibilities, we decided to utilize a water temperature sensor, and implement rating functionalities to allow the system learn user’s preference on the softness of yolk.

Scenarios, Storyboards, Sketches

Once having our ideas settled down, we created scenarios, storyboards, and sketches to help us check how the interaction will play out in context.

UI Design

To design the mobile app, we first roughed out wireframes and UI flow diagrams. I then redesigned the UI based on the initial concept from my collaborator Kosuke. The specs were updated to fit a iPhone 6 screen, and a more playful typeface was used to convey the happy and relaxing theme.


To evaluate and demonstrate our idea, we created 4 prototypes: Electronic prototype (Arduino), Physical prototype (3D Printed), Mobile prototype, Video prototype.

Each prototype had its own purpose. The electronic prototype with Arduino was built to evaluate how our smart timer enhance the experience of cooking boiled eggs, compared with an ordinary kitchen timer. The physical prototype was created to evaluate physical affordances of our smart egg timer. To evaluate the interaction of our mobile companion app, we created a mobile app prototype using Adobe Illustrator and Marvel Prototyping Tool. Finally, to demonstrate the concept in a short amount of time, we created a video prototype that showcased the key features of our product. This video was played in a loop on our Demo Day.