Offserv
Offserv is an offline-first emergency response app for alpine environments. It solves a critical problem: how do you call for help when you have no signal?
The app was built in a couple of hours at the district-wide HTL Vorarlberg hackathon by a three-person team, taking first place over 20+ competing teams and 60+ students.
In an alpine emergency (a fall, an injury, sudden weather), your phone is your lifeline. But above a certain altitude or deep in a remote valley, there is no signal. Standard emergency apps are useless. GPS still works, but there is nothing to call.
Offserv was designed to bridge that gap: navigate you toward the nearest signal, and dispatch help the moment a connection becomes available.
The solution required two independent systems working together, both entirely without an internet connection.
Offline Navigation
The app ships with a bundled CSV containing the location and coverage range of every GSM tower in Austria. Using the device's live GPS coordinates and compass heading, Offserv calculates the nearest signal field and renders a real-time directional arrow pointing you toward it. The entire dataset lives on the device. No internet required.
Emergency Alert
The moment the device detects even the weakest signal, the app automatically fires an SMS to emergency services. The message includes the user's GPS coordinates, altitude, and any situation details they've entered. SMS requires only a fraction of the signal strength needed for a voice call or data connection, making it ideal for marginal coverage.
All three of us were building. I worked on the core offline navigation logic, integrating the bundled GSM tower dataset with the device compass and GPS to calculate and render the directional arrow in real time.
I also took on the coordination side during the sprint: keeping us focused, making the scoping calls when time was tight, and helping with the final pitch for the judges.