With BMIzer the goal was to create a fresh, friendly bmi calculator.
The core idea was to use a draggable scale where the user could track current weight. Also, we wanted to simplify the interaction and use huge push targets to achieve minimal input effort.
As weight hopefully wouldn’t change too radically, it is sufficient to make fine adjustments each time, which the slider makes very easy. The other fixed parameters (height and gender) can safely reside in the settings for these will probably never change.
We wanted the ability for the user to specify their current mood, so as to show the correlation between general well-being and weight changes. Instead of displaying a long list of possible moods, we have simplified this down to just four icons (happy, neutral, sad, stressed). That enabled us to display them as large buttons at the bottom, so each day’s input consists of a drag, and a tap.
The user is then instantly rewarded by a quick evaluation of their current bmi, and a visual overview of their progress.