Meridian

Most condition-tracking apps are designed for the day you download them, when you are motivated and everything gets logged. Meridian's own data showed the opposite pattern: the people who needed the app most used it least, and the ones who dropped out did so in the middle of a flare — precisely when logging was hardest and most valuable.

Designing for the worst day

We made a rule early on: every core flow had to be completable one-handed, in under fifteen seconds, by someone in pain and out of patience. That single constraint killed about half the roadmap, including a rather beautiful charting feature I had already prototyped.

What survived was smaller and much better. A single tap logs a day as difficult. Detail is optional and can be added later, or never. The app stopped asking people to perform diligence they did not have to spare.

Honest empty states

The previous version congratulated people on streaks, which is a cruel mechanic when a broken streak means you were unwell. We removed every streak, badge, and nudge, and replaced them with a plain summary you could hand to a clinician.

Where it landed

Thirty-day retention nearly doubled. More usefully, the gap between healthy-week and flare-week logging almost closed — the app finally worked when it was needed.