Background
SAYA is a smart safety ring: discreet to wear, always within reach on the finger, with an intuitive click mechanism. From that click, a full emergency flow has to happen within seconds — a loud alarm on the device itself, notifications to chosen emergency contacts, a shared GPS location. The product promise hinges on hardware, smartphone, backend and push infrastructure all working precisely at the moment it matters.
That's the hard part: Bluetooth stacks, iOS and Android background behaviour, cloud signal chains, push-message platform quirks. If any link wobbles, the entire emergency call fails.
Solution
We delivered the mobile product and emergency infrastructure around the ring.
- Native iOS and Android apps. Swift for iOS, Kotlin for Android — no cross-platform shortcut. Bluetooth connection to the SAYA ring including reconnect behaviour, energy profiles and background lifecycle, so the ring responds even when the app isn't in the foreground.
- Emergency / SOS flow. Click on the ring → the app prioritises the emergency call → the relevant signals are dispatched without forcing users to navigate menus first.
- Strapi backend + hosting. User, contact and app data run through a Strapi backend we set up and operate. Data and configuration stay under our control, not in a third-party SaaS cloud.
- Firebase / push signal chain. Push notifications and messaging flow through Firebase and complementary mechanisms, so chosen emergency contacts are reached quickly — even if their device isn't actively in use.
- Location-based alerting. In an emergency the app shares the current GPS location so contacts don't just know that something happened — they know where.
Outcome
SAYA now has an unbroken safety solution spanning hardware, mobile app and cloud infrastructure. The ring fits everyday use, and the emergency flow is what it has to be: easy to trigger, technically resilient, invisible until it's needed.
More about the product at sa-ya.de.
Why this fits us
Hardware-driven emergency apps are their own discipline. UI design and marketing promises don't help when the Bluetooth stack drops a reconnect or Firebase throttles push messages on a particular profile. We enjoy that surface: platform depth on two mobile OSes, a robust backend architecture, and a signal chain that works under real-world conditions — not just in a demo video.