Signal Atlas

A cross-platform application for crowdsourced mobile signal coverage mapping, available as a web PWA, a native iOS app, and a native Android app — all backed by a shared Kotlin/Spring Boot API.

Users record their mobile signal quality during trips, and Signal Atlas visualizes the collected data on an interactive map — color-coded by signal strength (red for no signal/2G, orange for 3G, green for 4G, blue for 5G). This helps identify dead zones and compare carrier coverage across different routes.

Platforms

• Web — Angular 19 progressive web app with Leaflet maps, Chart.js analytics, and offline support.
• iOS — native Swift 6 / SwiftUI app using Core Location for GPS-based signal recording.
• Android — native Kotlin / Jetpack Compose app with MapLibre GL maps.
• Backend — Spring Boot 3.4 + Kotlin + PostgreSQL, with an OpenAPI-first design that auto-generates the API clients for every platform.

Key features

• GPS-based recording flow that captures signal measurements along a route.
• Interactive coverage map color-coded by signal quality (2G through 5G).
• Route history and per-route detail views.
• Analytics dashboard with charts and carrier coverage comparison.
• Privacy-first design: anonymous device sessions and user-defined privacy zones.
• Fully bilingual (English / German).