Overview
Proofmark Camera is deliberately simple: it's a camera that overlays a timestamp, GPS coordinates, and address onto every photo. No account. No ads. No internet connection required. Always saves to your device.
It's a tool for tradespeople, property managers, delivery drivers, and anyone else who needs verifiable photographic evidence as part of their workflow.
The Philosophy
Most camera apps with timestamps are either cluttered with ads, require an account, or upload your photos to a server you don't control. That's a problem when your photos contain sensitive job site information.
Proofmark Camera does everything on-device. The overlay is computed locally. The photo is saved to your camera roll. Nothing leaves your phone unless you choose to share it.
Design Constraints
The design had to work with one hand, in bright sunlight, with dirty hands. These were the three constraints I kept returning to throughout the process.
One hand: Large tap targets, no precision required. The main CTA is a large bottom button. All settings are accessible from the viewfinder with no deep navigation.
Bright sunlight: High-contrast UI. The overlay on photos uses a semi-opaque black background behind the text to ensure readability regardless of photo brightness.
Dirty hands: The fewer interactions required to take a documented photo, the better. Default settings remember your last configuration.
Technical Notes
GPS accuracy handling: The app displays accuracy radius alongside coordinates. If GPS accuracy is poor (>50m), the accuracy indicator turns amber. This is honest UX — it tells you when to trust the data.
Address geocoding: Done offline via a bundled dataset for major cities. Falls back gracefully when offline.
Photo overlay: Computed in React Native using canvas — no server round-trip required.
What I Didn't Build
I was tempted to add cloud backup, team sharing, and project organisation. I didn't. The product is better for it. Every feature that requires an account adds friction that hurts the core use case.
A product that does one thing perfectly is more valuable than one that does many things adequately.
Status
Live on iOS and Android. Free, with no plans to monetise the base product.