Lume — Smart Energy Bill Management App

Lead UX/UI Designer. Boolean × IMILLE, five-month project, team of three.

Lume is an app that helps people understand and manage their energy bills. This was Davide's first UX/UI project, with research conducted and synthesized entirely by hand.

The research combined a survey of 77 users aged 30 to 55 with 8 in-depth one-to-one qualitative interviews, alongside competitor benchmarking and usability testing.

Asked what they would change about their bill experience, users pointed to clarity and simplicity (25%), better graphics and UX (16.1%), and cost detail (6.5%), with 22.6% giving other, spontaneous responses.

The resulting design includes a real-time consumption dashboard, gamified saving challenges, educational tooltips, and Lumy, the brand's mascot.

The Design System complies with WCAG 2.1 AA, covering color contrast, touch target size, and visible focus states.

Deliverables

User flows, information architecture, wireframes, prototypes, UI, and a complete Design System.

Lume app hero screens: energy dashboard, bill details with cost breakdown, and the Lumy energy coach's weekly actions, alongside the project overview, goals and challenges.
Onboarding screen introducing Lumy, the app's mascot, with a warm welcome message.
Phone mockups of the bill details, consumption dashboard and profile screens, next to the six-phase project roadmap: Discovery & Strategy, UX Research, Ideation & Lead UX, Validation, UI & Content, Prototype & Handoff.
Three app screens showing the electricity and gas overview, the real-time consumption dashboard, and Lumy's weekly actions.
Five user research insight cards on bill anxiety and complexity, alongside the key insight panel and survey results on what users would change about their bill experience.
Utility switch screen: a single toggle to move between electricity and gas without losing context.
Close-up of the live consumption dashboard reading 124 kWh.
Lumy the mascot celebrating next to the weekly saving challenges screen.
Gamification badges (The Champion, Tree Hugger, CoinHero, Night Owl) and the Lumy coach screen, shown alongside photos of users interacting with the app.
Latest bill screen showing payment status, daytime versus nighttime usage split, and the billed amount.
Design System components, Lumy's mascot expressions, the Lume brand identity, color palette, typography, and the project's landing page and team credits.