diff --git a/.gitignore b/.gitignore
index 6acbbf7..f83423e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .git.safe
+/node_modules
diff --git a/Gruntfile.js b/Gruntfile.js
new file mode 100644
index 0000000..42595b0
--- /dev/null
+++ b/Gruntfile.js
@@ -0,0 +1,47 @@
+module.exports = function(grunt) {
+
+  // Project configuration.
+  grunt.initConfig({
+    jshint: {
+      options: {
+        curly: true,
+        eqeqeq: true,
+        immed: true,
+        latedef: true,
+        newcap: true,
+        noarg: true,
+        sub: true,
+        undef: true,
+        boss: true,
+        eqnull: true,
+        node: true,
+        es5: true,
+        globals: {
+          jasmine: false,
+          describe: false,
+          beforeEach: false,
+          afterEach: false,
+          expect: false,
+          it: false,
+          spyOn: false,
+          $: false,
+          cordova: false,
+          launchnavigator: false,
+          window: false,
+          document: false,
+          ons: false,
+          navigator: false,
+          google: false,
+          FCMPlugin: false,
+          device: false,
+          plugins: false,
+          addFixture: false,
+          truncateSql: false
+        }
+      },
+      all: ['Gruntfile.js', 'www/**/*.js']
+    }
+  });
+
+  grunt.loadNpmTasks('grunt-contrib-jshint');
+};
diff --git a/package.json b/package.json
index 3ac1429..252f6de 100644
--- a/package.json
+++ b/package.json
@@ -8,5 +8,9 @@
       "ios"
     ]
   },
-  "description": "A Google Firebase Firestore plugin"
+  "description": "A Google Firebase Firestore plugin",
+  "devDependencies": {
+    "grunt": "^1.0.1",
+    "grunt-contrib-jshint": "^1.1.0"
+  }
 }
diff --git a/src/android/uk/co/reallysmall/cordova/plugin/firestore/InitialiseHandler.java b/src/android/uk/co/reallysmall/cordova/plugin/firestore/InitialiseHandler.java
index 890dd42..a37168f 100644
--- a/src/android/uk/co/reallysmall/cordova/plugin/firestore/InitialiseHandler.java
+++ b/src/android/uk/co/reallysmall/cordova/plugin/firestore/InitialiseHandler.java
@@ -8,10 +8,13 @@
 import org.apache.cordova.CallbackContext;
 import org.json.JSONArray;
 import org.json.JSONException;
+import org.json.JSONObject;
 
 
 public class InitialiseHandler implements ActionHandler {
 
+    public static final String PERSIST = "persist";
+    public static final String DATE_PREFIX = "datePrefix";
     private FirestorePlugin firestorePlugin;
 
     public InitialiseHandler(FirestorePlugin firestorePlugin) {
@@ -25,11 +28,23 @@ public boolean handle(final JSONArray args, CallbackContext callbackContext) {
             if (firestorePlugin.getDatabase() == null) {
                 Log.d(FirestorePlugin.TAG, "Initialising Firestore...");
 
-                final boolean persist = args.getBoolean(0);
+                final JSONObject options = args.getJSONObject(0);
 
                 FirebaseFirestore.setLoggingEnabled(true);
                 firestorePlugin.setDatabase(FirebaseFirestore.getInstance());
 
+                boolean persist = false;
+
+                if (options.has(PERSIST) && options.getBoolean(PERSIST)) {
+                    persist = true;
+                }
+
+                if (options.has(DATE_PREFIX)) {
+                    JSONDateWrapper.setDatePrefix(options.getString(DATE_PREFIX));
+                }
+
+                Log.d(FirestorePlugin.TAG, "Setting Firestore persistance to " + persist);
+
                 FirebaseFirestoreSettings settings = new FirebaseFirestoreSettings.Builder()
                         .setPersistenceEnabled(persist)
                         .build();
diff --git a/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONDateWrapper.java b/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONDateWrapper.java
index 72c64e3..8375afc 100644
--- a/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONDateWrapper.java
+++ b/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONDateWrapper.java
@@ -3,12 +3,19 @@
 import java.util.Date;
 
 public class JSONDateWrapper extends Date {
+
+    private static String datePrefix = "__DATE:";
+
     public JSONDateWrapper(Date date) {
         super(date.getTime());
     }
 
+    public static void setDatePrefix(String datePrefix) {
+        JSONDateWrapper.datePrefix = datePrefix;
+    }
+
     @Override
     public String toString() {
-        return "__DATE(" + this.getTime() + ")";
+        return this.datePrefix + this.getTime();
     }
 }
diff --git a/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONHelper.java b/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONHelper.java
index aced40b..50de746 100644
--- a/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONHelper.java
+++ b/src/android/uk/co/reallysmall/cordova/plugin/firestore/JSONHelper.java
@@ -32,48 +32,6 @@ static JSONObject toJSON(Map<String, Object> values) throws JSONException {
         return result;
     }
 
-//    static Map<String, Object> jsonToMap(JSONObject json) throws JSONException {
-//        Map<String, Object> retMap = new HashMap<String, Object>();
-//
-//        if (json != JSONObject.NULL) {
-//            retMap = toMap(json);
-//        }
-//        return retMap;
-//    }
-
-//    static Map<String, Object> toMap(JSONObject object) throws JSONException {
-//        Map<String, Object> map = new HashMap<String, Object>();
-//
-//        Iterator<String> keysItr = object.keys();
-//        while (keysItr.hasNext()) {
-//            String key = keysItr.next();
-//            Object value = object.get(key);
-//
-//            if (value instanceof JSONArray) {
-//                value = toList((JSONArray) value);
-//            } else if (value instanceof JSONObject) {
-//                value = toMap((JSONObject) value);
-//            }
-//            map.put(key, value);
-//        }
-//        return map;
-//    }
-//
-//
-//    static List<Object> toList(JSONArray array) throws JSONException {
-//        List<Object> list = new ArrayList<Object>();
-//        for (int i = 0; i < array.length(); i++) {
-//            Object value = array.get(i);
-//            if (value instanceof JSONArray) {
-//                value = toList((JSONArray) value);
-//            } else if (value instanceof JSONObject) {
-//                value = toMap((JSONObject) value);
-//            }
-//            list.add(value);
-//        }
-//        return list;
-//    }
-
     static Object toSettable(Object value) {
 
         Object result = value;
diff --git a/www/browser/firestore.js b/www/browser/firestore.js
index 4a189ff..31ead93 100644
--- a/www/browser/firestore.js
+++ b/www/browser/firestore.js
@@ -1,3 +1,5 @@
+/* global firebase: false, Promise: false */
+
 var PLUGIN_NAME = 'Firestore';
 
 var loadJS = function(url, implementationCode, location) {
@@ -10,24 +12,26 @@ var loadJS = function(url, implementationCode, location) {
   location.appendChild(scriptTag);
 };
 
-function Firestore(persist, firebaseOptions) {
+function Firestore(options, resolve) {
 
   var self = this;
 
   var initialise = function() {
 
-    firebase.initializeApp(firebaseOptions);
+    firebase.initializeApp(options.browser);
 
-    if (persist) {
+    if (options.persist) {
       firebase.firestore().enablePersistence().then(function() {
         self.database = firebase.firestore();
+        resolve(self);
       });
     } else {
       self.database = firebase.firestore();
+      resolve(self);
     }
-  }
-  loadJS('https://www.gstatic.com/firebasejs/4.5.0/firebase.js', function() {
-    loadJS('https://www.gstatic.com/firebasejs/4.5.0/firebase-firestore.js', initialise, document.body);
+  };
+  loadJS('https://www.gstatic.com/firebasejs/4.7.0/firebase.js', function() {
+    loadJS('https://www.gstatic.com/firebasejs/4.7.0/firebase-firestore.js', initialise, document.body);
   }, document.body);
 
 }
@@ -37,7 +41,9 @@ Firestore.prototype.get = function() {
 };
 
 module.exports = {
-  initialise: function(persist, firebaseOptions) {
-    return new Firestore(persist, firebaseOptions);
+  initialise: function(options) {
+    return new Promise(function(resolve, reject) {
+      var db = new Firestore(options, resolve);
+    });
   }
 };
diff --git a/www/firestore.js b/www/firestore.js
index 225f755..ba547be 100644
--- a/www/firestore.js
+++ b/www/firestore.js
@@ -1,19 +1,21 @@
+/* global Promise: false */
+
 var exec = require('cordova/exec');
 var utils = require("cordova/utils");
 
 var PLUGIN_NAME = 'Firestore';
+var FirestoreOptions = {
+  "datePrefix": "__DATE:",
+  "persist": true
+};
 
-function Firestore(persist, datePrefix) {
-  if (datePrefix === undefined) {
-    this.datePrefix = "__DATE(";
-  } else {
-    this.datePrefix = datePrefix;
+function Firestore(options) {
+  FirestoreOptions = options;
+  if (FirestoreOptions.datePrefix === undefined) {
+    this.datePrefix = "__DATE:";
   }
 
-  if (persist === undefined) {
-    persist = true;
-  }
-  exec(function() {}, null, PLUGIN_NAME, 'initialise', [persist]);
+  exec(function() {}, null, PLUGIN_NAME, 'initialise', [FirestoreOptions]);
 }
 
 Firestore.prototype = {
@@ -25,116 +27,106 @@ Firestore.prototype = {
   }
 };
 
-function Query(ref, queryType, value) {
-  this._ref = ref;
-  this._ref._queries.push({
-    "queryType": queryType,
-    "value": value
-  });
-}
-
-Query.prototype = {
-  endAt: function(snapshotOrVarArgs) {
-    return new Query(this._ref, "endAt", snapshotOrVarArgs);
-  },
-  endBefore: function(snapshotOrVarArgs) {
-    return new Query(this._ref, "endBefore", snapshotOrVarArgs);
-  },
-  limit: function(limit) {
-    return new Query(this._ref, "limit", limit);
-  },
-  orderBy: function(field, direction) {
-    if (direction === undefined) {
-      direction = "ASCENDING";
-    }
+function DocumentSnapshot(data) {
+  this._data = data;
 
-    var orderByField = {
-      "field": field,
-      "direction": direction
-    };
-    return new Query(this._ref, "orderBy", orderByField);
-  },
-  get: function() {
-    var args = [this._ref._path, this._ref._queries];
+  if (data.exists) {
+    var keys = Object.keys(this._data._data);
+    for (var i = 0; i < keys.length; i++) {
+      var key = keys[i];
 
-    return new Promise(function(resolve, reject) {
-      exec(resolve, reject, PLUGIN_NAME, 'collectionGet', args);
-    }).then(function(data) {
-      return new QuerySnapshot(data);
-    });
-  },
-  onSnapshot: function(callback, options) {
+      if (typeof this._data._data[key] === 'string' && this._data._data[key].startsWith(FirestoreOptions.datePrefix)) {
+        var length = this._data._data[key].length;
+        var prefixLength = FirestoreOptions.datePrefix.length;
 
-    callbackId = utils.createUUID();
-    var args = [this._ref._path, this._ref._queries, options, callbackId];
+        var timestamp = this._data._data[key].substr(prefixLength, length - prefixLength);
 
-    var callbackWrapper = function(data) {
-      callback(new QuerySnapshot(data));
+        this._data._data[key] = new Date(parseInt(timestamp));
+      }
     }
-    exec(callbackWrapper, function() {}, PLUGIN_NAME, 'collectionOnShapshot', args);
+  }
+}
 
-    return function() {
-      exec(function() {}, function() {}, PLUGIN_NAME, 'collectionUnsubscribe', [callbackId]);
-    };
-  },
-  startAfter: function(snapshotOrVarArgs) {
-    return new Query(this._ref, "startAfter", snapshotOrVarArgs);
+DocumentSnapshot.prototype = {
+  _fieldPath: function(obj, i) {
+    return obj[i];
   },
-  startAt: function(snapshotOrVarArgs) {
-    return new Query(this._ref, "startAt", snapshotOrVarArgs);
+  data: function() {
+    return this._data._data;
   },
-  where: function(fieldPath, opStr, passedValue) {
-    var value;
-    if (passedValue instanceof Date) {
-      value = "__DATE(" + passedValue.getTime() + ")";
-    } else {
-      value = passedValue;
-    }
-    var whereField = {
-      "fieldPath": fieldPath,
-      "opStr": opStr,
-      "value": value
-    };
-    return new Query(this._ref, "where", whereField);
+  get: function(fieldPath) {
+    return fieldPath.split('.').reduce(this._fieldPath, this._data);
   }
 };
 
-function CollectionReference(path, id) {
-  this._path = path;
-  this._id = id;
-  this._ref = this;
-  this._queries = [];
-}
-
-CollectionReference.prototype = Object.create(Query.prototype, {
-  firestore: {
+Object.defineProperties(DocumentSnapshot.prototype, {
+  exists: {
     get: function() {
-      throw "CollectionReference.firestore: Not supported";
+      return this._data.exists;
     }
   },
   id: {
     get: function() {
-      return this._id;
+      return this._data.id;
     }
   },
-  parent: {
+  metadata: {
     get: function() {
-      throw "CollectionReference.parent: Not supported";
+      throw "DocumentReference.metadata: Not supported";
+    }
+  },
+  ref: {
+    get: function() {
+      return this._data.ref;
     }
   }
 });
 
-CollectionReference.prototype.add = function(data) {
-  var args = [this._path, data];
+function QuerySnapshot(data) {
+  this._data = data;
+}
 
-  return new Promise(function(resolve, reject) {
-    exec(resolve, reject, PLUGIN_NAME, 'collectionAdd', args);
-  });
+QuerySnapshot.prototype = {
+  forEach: function(callback, thisArg) {
+    var keys = Object.keys(this._data.docs);
+    for (var i = 0; i < keys.length; i++) {
+      callback(new DocumentSnapshot(this._data.docs[i]));
+    }
+  }
 };
 
-CollectionReference.prototype.doc = function(id) {
-  return new DocumentReference(this, id);
-}
+Object.defineProperties(QuerySnapshot.prototype, {
+  docChanges: {
+    get: function() {
+      throw "QuerySnapshot.docChanges: Not supported";
+    }
+  },
+  docs: {
+    get: function() {
+      return this._data.docs;
+    }
+  },
+  empty: {
+    get: function() {
+      return this._data.docs.length === 0;
+    }
+  },
+  metadata: {
+    get: function() {
+      throw "QuerySnapshot.metadata: Not supported";
+    }
+  },
+  query: {
+    get: function() {
+      throw "QuerySnapshot.query: Not supported";
+    }
+  },
+  size: {
+    get: function() {
+      return this._data.docs.length;
+    }
+  }
+});
 
 function DocumentReference(collectionReference, id) {
   this._id = id;
@@ -208,7 +200,6 @@ DocumentReference.prototype = {
   }
 };
 
-
 Object.defineProperties(DocumentReference.prototype, {
   firestore: {
     get: function() {
@@ -227,109 +218,121 @@ Object.defineProperties(DocumentReference.prototype, {
   }
 });
 
-function DocumentSnapshot(data) {
-  this._data = data;
+function Query(ref, queryType, value) {
+  this._ref = ref;
+  this._ref._queries.push({
+    "queryType": queryType,
+    "value": value
+  });
+}
 
-  if (data.exists) {
-    var keys = Object.keys(this._data._data);
-    for (var i = 0; i < keys.length; i++) {
-      var key = keys[i];
+Query.prototype = {
+  endAt: function(snapshotOrVarArgs) {
+    return new Query(this._ref, "endAt", snapshotOrVarArgs);
+  },
+  endBefore: function(snapshotOrVarArgs) {
+    return new Query(this._ref, "endBefore", snapshotOrVarArgs);
+  },
+  limit: function(limit) {
+    return new Query(this._ref, "limit", limit);
+  },
+  orderBy: function(field, direction) {
+    if (direction === undefined) {
+      direction = "ASCENDING";
+    }
 
-      if (typeof this._data._data[key] === 'string' && this._data._data[key].startsWith("__DATE(")) {
-        var length = this._data._data[key].length;
-        var wrapperLength = "__DATE(".length;
+    var orderByField = {
+      "field": field,
+      "direction": direction
+    };
+    return new Query(this._ref, "orderBy", orderByField);
+  },
+  get: function() {
+    var args = [this._ref._path, this._ref._queries];
 
-        var timestamp = this._data._data[key].substr(wrapperLength, length - wrapperLength - 1);
+    return new Promise(function(resolve, reject) {
+      exec(resolve, reject, PLUGIN_NAME, 'collectionGet', args);
+    }).then(function(data) {
+      return new QuerySnapshot(data);
+    });
+  },
+  onSnapshot: function(callback, options) {
 
-        this._data._data[key] = new Date(parseInt(timestamp));
-      }
-    }
-  }
-}
+    var callbackId = utils.createUUID();
+    var args = [this._ref._path, this._ref._queries, options, callbackId];
 
-DocumentSnapshot.prototype = {
-  _fieldPath: function(obj, i) {
-    return obj[i];
+    var callbackWrapper = function(data) {
+      callback(new QuerySnapshot(data));
+    };
+    exec(callbackWrapper, function() {}, PLUGIN_NAME, 'collectionOnShapshot', args);
+
+    return function() {
+      exec(function() {}, function() {}, PLUGIN_NAME, 'collectionUnsubscribe', [callbackId]);
+    };
   },
-  data: function() {
-    return this._data._data;
+  startAfter: function(snapshotOrVarArgs) {
+    return new Query(this._ref, "startAfter", snapshotOrVarArgs);
   },
-  get: function(fieldPath) {
-    return fieldPath.split('.').reduce(this._fieldPath, this._data);
+  startAt: function(snapshotOrVarArgs) {
+    return new Query(this._ref, "startAt", snapshotOrVarArgs);
+  },
+  where: function(fieldPath, opStr, passedValue) {
+    var value;
+    if (passedValue instanceof Date) {
+      value = Firestore.datePrefix + passedValue.getTime();
+    } else {
+      value = passedValue;
+    }
+    var whereField = {
+      "fieldPath": fieldPath,
+      "opStr": opStr,
+      "value": value
+    };
+    return new Query(this._ref, "where", whereField);
   }
 };
 
-Object.defineProperties(DocumentSnapshot.prototype, {
-  exists: {
+function CollectionReference(path, id) {
+  this._path = path;
+  this._id = id;
+  this._ref = this;
+  this._queries = [];
+}
+
+CollectionReference.prototype = Object.create(Query.prototype, {
+  firestore: {
     get: function() {
-      return this._data.exists;
+      throw "CollectionReference.firestore: Not supported";
     }
   },
   id: {
     get: function() {
-      return this._data.id;
-    }
-  },
-  metadata: {
-    get: function() {
-      throw "DocumentReference.metadata: Not supported";
+      return this._id;
     }
   },
-  ref: {
+  parent: {
     get: function() {
-      return this._data.ref;
+      throw "CollectionReference.parent: Not supported";
     }
   }
 });
 
+CollectionReference.prototype.add = function(data) {
+  var args = [this._path, data];
 
-function QuerySnapshot(data) {
-  this._data = data;
-}
+  return new Promise(function(resolve, reject) {
+    exec(resolve, reject, PLUGIN_NAME, 'collectionAdd', args);
+  });
+};
 
-QuerySnapshot.prototype = {
-  forEach: function(callback, thisArg) {
-    var keys = Object.keys(this._data.docs);
-    for (var i = 0; i < keys.length; i++) {
-      callback(new DocumentSnapshot(this._data.docs[i]));
-    }
-  }
+CollectionReference.prototype.doc = function(id) {
+  return new DocumentReference(this, id);
 };
 
-Object.defineProperties(QuerySnapshot.prototype, {
-  docChanges: {
-    get: function() {
-      throw "QuerySnapshot.docChanges: Not supported";
-    }
-  },
-  docs: {
-    get: function() {
-      return this._data.docs;
-    }
-  },
-  empty: {
-    get: function() {
-      return this._data.docs.length === 0;
-    }
-  },
-  metadata: {
-    get: function() {
-      throw "QuerySnapshot.metadata: Not supported";
-    }
-  },
-  query: {
-    get: function() {
-      throw "QuerySnapshot.query: Not supported";
-    }
-  },
-  size: {
-    get: function() {
-      return this._data.docs.length;
-    }
-  }
-});
 module.exports = {
-  initialise: function() {
-    return new Firestore();
+  initialise: function(options) {
+    return new Promise(function(resolve, reject) {
+      resolve(new Firestore(options));
+    });
   }
 };