Il-Young Jeong
Was It Just Me?
Core trick
Anonymous one-tap signals are bucketed by location and time window, and a cluster threshold reveals when several nearby users report at once.
Tags
Description
Was It Just Me? is a low-power neighborhood signal app that runs quietly in the background and lets users send a signal within one second when they notice something unusual nearby. Instead of requiring a full report, the product focuses on immediate, lightweight input: a user senses something, triggers a signal, and check if it was not just them.
By aggregating signals that happen around the same time in the same area, the app helps estimate whether there may be a meaningful local situation developing. If many nearby users send signals simultaneously, the system can surface a rough sense of local risk or urgency while preserving user anonymity.
README excerpt
<div align="center"> # Was It Just Me? ### A privacy-preserving neighborhood "signal" map — notice something, anonymously, with one gesture. **▶ Live demo: https://finejuly.github.io/Was-It-Just-Me/** *Built for Claude Build Day.* </div> --- ## The idea You feel a tremor, hear a strange boom, see the power flicker — and you wonder: **was it just me, or did the whole neighborhood notice too?** "Was It Just Me?" answers that with the lowest-friction signal possible. There is exactly **one action**: *"I noticed something."* No category, no description, no severity, no account. One hotkey (or tap) drops a single anonymous dot on a shared map. When several dots light up the same area in the same minutes, you have your answer — collective noticing, with no one's privacy spent to get it. It is deliberately **not** a crime-reporting, surveillance, or policing tool. It never asks *what* happened, and it makes no claim that anything did. ## Privacy is the whole point A naive "drop my location on a map" app would leak exactly the thing it should protect. So privacy is enforced **at capture, on the client, before anything is stored or shown**: - **Jittered + bucketed + coarsened.** Every signal's coordinates are randomized and snapped to a coarse bucket. The dot you see is never the sender's true location. - **Raw location is never persisted or transmitted.** The only code that reads the device's real position lives in one file (`src/ui/geo.ts`); its output is routed straigh