We built ultra-fast Android and iOS apps using Flutter for both tefillin providers and requesters.

Providers can turn their availability on and are tracked using low-battery background geo-tracking.

When request comes in, we use Tile38 real-time geofencing and Firebase cloud-messaging to notify only relevant providers.

After a provider accepts the app notifies the requester and their location is tracked until the wrapp is complete.  Mazal Tov!