UPDATE: As of AngularFire 0.8.x, one can use $asArray() to obtain a sorted array of the records and this answer is no longer necessary
The correct way to iterate values in an angularFire object is by using $getIndex(). You have this in your code above, but did not utilize it in the for loop.
Since you are already using the angularFire lib (syncData is the angularFire-seed service that uses angularFire), there is no need to worry about calling $apply() or any of the other complexities of coaxing data into Angular detailed in the previous answer (which is a good response for a raw Firebase/Angular implementation).
Instead, just change your for loop to iterate the keys instead of the angularFire instance:
syncData('everyone').$bind($scope, 'everyone').then(function() {
var keys = $scope.everyone.$getIndex();
// utilizing Angular's helpers
angular.forEach(keys, function(key) {
console.log(key, $scope.everyone[key]);
});
// or as a for loop
for(var i=0, len = keys.length; i < len; i++) {
console.log(keys[i], $scope.everyone[keys[i]]);
}
});
To utilize the object in the DOM, use ng-repeat:
<ul>
<li ng-repeat="(key,user) in everyone">{{key}}, {{user|json}}</li>
</ul>