BackgroundGeolocation Geofence API

geofence.js

// Add custom longpress event for adding GeoFence with hard-coded radius 200m.
google.maps.event.addListener(app.map, 'longpress', function(e) {
    if (app.geofence) {
        app.geofence.setMap(null);
    }
    // Add the geofence with BackgroundGeolocation plugin
    bgGeo.addGeofence({
        identifier: 'MyGeofence',
        radius: 200,
        latitude: e.latLng.lat(),
        longitude: e.latLng.lng()
    }, function() {
        // If iOS successfully created your geofence, success-callback runs.
        // NOTE:  iOS only allows 20 geofences ON ALL APPS COMBINED.
        // ie: operating-system-wide limit of 20.  Thus success callback here is important.
        app.geofence = new google.maps.Circle({
            fillColor: '#00cc00',
            fillOpacity: 0.4,
            strokeOpacity: 0,
            radius: 200,
            center: e.latLng,
            map: app.map
        });
    });
});

// Finally, we set up a "geofence" listener.  ALL geofence crossings execute
// this callback.  Use the supplied identifier to map to a particular geofence
bgGeo.onGeofence(function(identifier) {
    console.log('[js] Geofence ENTER: ', identifier);
    switch (identifier) {
        case 'HOME':
            break;
        case 'OFFICE':
            break;
    }
});