AngularJS / Javascript Utility Service compiled of different functions. See comment below for breakdown.

angular-utility.js

(function (ng, $) {
    angular.module('helper')
        .factory('utils', ['$timeout', '$window', function ($timeout, $window) {

            var utils = {};

            // http://ng.malsup.com/#!/getting-started-with-$q
            // A nice way of calling $timeout
            /*
                utils.wait(5).then(function(msg) {
                    // Success
                }, function() {
                    // Error
                });
            */
            utils.wait = function (seconds) {
                // return the $timeout's promise
                return $timeout(function () {
                    // the return from this function is the value passed to the promise's success handler (the resolve value)
                    return (seconds + ' seconds have elapsed');
                }, seconds * 1000);
            };

            // Load Google Maps w/ promise
            utils.loadGoogleMaps = function () {
                return utils.loadScript("http://maps.google.com/maps/api/js?v=3&sensor=false", function () {
                    return $window.google;
                }, "Google Maps");
            };

            // Load script (local or external) w/ promise
            utils.loadScript = function (scriptSrc, scriptLoadedCheck, name) {
                var script = document.createElement("script");
                script.src = scriptSrc;
                document.getElementsByTagName("head")[0].appendChild(script);

                return utils.poll(scriptLoadedCheck, null, null, name);
            };

            // Polls to check when a variable is defined. Returns a promise
            utils.poll = function (whenReady, interval, timeout, name) {
                var deferred = $q.defer(),
                    interval = parseInt(arguments[1], 10) || 50, // default to 50 milliseconds
                    timeout = parseInt(arguments[2], 10) || Infinity; // default: poll until found

                (function poll() {
                    var me = this;
                    if (whenReady.apply(me)) { // poll check func satisfied
                        deferred.resolve();
                    } else if ((timeout -= interval) > 0) { // poll again
                        deferred.notify("Polling " + (name || ""))
                        $timeout(poll, interval);
                    } else { // timeout reached
                        deferred.reject("Poll timeout reached " + (name || ""));
                    }
                }());

                return deferred.promise;
            };

            // http://stackoverflow.com/a/4994244/654708
            // Check if an object is empty or has no properties of its own.
            utils.isEmpty = function (obj) {
                // null and undefined are "empty"
                if (obj == null) return true;

                // Assume if it has a length property with a non-zero value
                // that that property is correct.
                if (obj.length > 0) return false;
                if (obj.length === 0) return true;

                // Otherwise, does it have any properties of its own?
                // Note that this doesn't handle
                // toString and valueOf enumeration bugs in IE < 9
                for (var key in obj) {
                    if (hasOwnProperty.call(obj, key)) return false;
                }

                return true;
            };

            // http://stackoverflow.com/a/3855394/654708
            // Creates an object from querty string with name and values
            // Use utils.qs.isEmpty to see if any values are present
            utils.qs = (function (a) {
                var b = {
                    isEmpty: true
                };
                if (a == "") return b;
                for (var i = 0; i < a.length; ++i) {
                    var p = a[i].split('=');
                    if (p.length != 2) continue;
                    b[p[0]] = decodeURIComponent(p[1].replace(/\+/g, " "));
                    if (b.isEmpty) {
                        b.isEmpty = false;
                    }
                }
                return b;
            })(window.location.search.substr(1).split('&'));


            // https://github.com/yearofmoo/AngularJS-Scope.SafeApply
            // Calls Angular $apply only when not in digest or apply phase
            utils.safeApply = function () {
                var $scope, fn, force = false;
                if (arguments.length == 1) {
                    var arg = arguments[0];
                    if (typeof arg == 'function') {
                        fn = arg;
                    } else {
                        $scope = arg;
                    }
                } else {
                    $scope = arguments[0];
                    fn = arguments[1];
                    if (arguments.length == 3) {
                        force = !! arguments[2];
                    }
                }
                $scope = $scope || this;
                fn = fn || function () {};
                if (force || !($scope.$$phase || $scope.$root.$$phase)) {
                    $scope.$apply ? $scope.$apply(fn) : $scope.apply(fn);
                } else {
                    fn();
                }
            };

            // http://davidwalsh.name/javascript-debounce-function
            /*
                            var myEfficientFn = utils.debounce(function() {
                            // All the taxing stuff you do
                            }, 250);
                            window.addEventListener('resize', myEfficientFn);
                        */
            utils.debounce = function (func, wait, immediate) {
                var timeout;
                return function () {
                    var context = this,
                        args = arguments;
                    clearTimeout(timeout);
                    timeout = setTimeout(function () {
                        timeout = null;
                        if (!immediate) func.apply(context, args);
                    }, wait);
                    if (immediate && !timeout) func.apply(context, args);
                };
            },

            // Checks if current device is a touch device
            utils.isTouchDevice = function () {
                return 'ontouchstart' in $window || !! (navigator.msMaxTouchPoints);
            };

            // http://detectmobilebrowsers.com/
            // Checks user agent to determine if user is on a mobile
            utils.isMobile = function () {
                var a = $window.navigator.userAgent || $window.navigator.vendor || $window.opera;
                return /(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|mobile.+firefox|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows (ce|phone)|xda|xiino/i.test(a) || /1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(a.substr(0, 4));
            };

            return utils;
        }]);
})(angular, window.jQuery || angular.element);

AngularJS/Javascript Utility Service compiled of different handy functions including:

• wait - Convenience wrapper for $timeout
• isEmpty - Check if a passed object is empty or has no properties of its own
• qs - Creates an object from query string with name and values
• poll - Polls that returns a promise. See utils.loadScript() for example
• safeApply - $safeApply for Angular
• debounce - Helps limit function calls on a chatty events e.g. window resize
• isTouchDevice - Returns true if current device is a touch device
• isMobile - Returns true if current device is a mobile