diff --git a/lib/modules/database/reference.js b/lib/modules/database/reference.js
index 7cc4e478..31753d75 100644
--- a/lib/modules/database/reference.js
+++ b/lib/modules/database/reference.js
@@ -5,7 +5,7 @@ import Query from './query.js';
 import Snapshot from './snapshot';
 import Disconnect from './disconnect';
 import ReferenceBase from './../../utils/ReferenceBase';
-import { isFunction, isObject, tryJSONParse, tryJSONStringify, generatePushID } from './../../utils';
+import { promiseOrCallback, isFunction, isObject, tryJSONParse, tryJSONStringify, generatePushID } from './../../utils';
 
 // Unique Reference ID for native events
 let refId = 1;
@@ -64,70 +64,110 @@ export default class Reference extends ReferenceBase {
     this._refListeners = {};
     this._database = database;
     this._query = new Query(this, path, existingModifiers);
-    // TODO this.log.debug('Created new Reference', this._refId, this.path);
+    this.log = this._database.log;
+    this.log.debug('Created new Reference', this._refId, this.path);
   }
 
   /**
+   * By calling `keepSynced(true)` on a location, the data for that location will
+   * automatically be downloaded and kept in sync, even when no listeners are
+   * attached for that location. Additionally, while a location is kept synced,
+   *  it will not be evicted from the persistent disk cache.
    *
+   * @link https://firebase.google.com/docs/reference/android/com/google/firebase/database/Query.html#keepSynced(boolean)
    * @param bool
    * @returns {*}
    */
   keepSynced(bool: boolean) {
-    return this._database._native.keepSynced(this.path, bool);
+    return this._database._native.keepSynced(this._refId, this.path, this._query.getModifiers(), bool);
   }
 
   /**
+   * Writes data to this Database location.
    *
+   * @link https://firebase.google.com/docs/reference/js/firebase.database.Reference#set
    * @param value
-   * @returns {*}
+   * @param onComplete
+   * @returns {Promise}
    */
-  set(value: any) {
-    return this._database._native.set(this.path, this._serializeAnyType(value));
+  set(value: any, onComplete?: Function): Promise {
+    return promiseOrCallback(
+      this._database._native.set(this.path, this._serializeAnyType(value)),
+      onComplete,
+    );
   }
 
   /**
+   * Sets a priority for the data at this Database location.
    *
+   * @link https://firebase.google.com/docs/reference/js/firebase.database.Reference#setPriority
    * @param priority
-   * @returns {*}
+   * @param onComplete
+   * @returns {Promise}
    */
-  setPriority(priority: string | number | null) {
+  setPriority(priority: string | number | null, onComplete?: Function): Promise {
     const _priority = this._serializeAnyType(priority);
-    return this._database._native.setPriority(this.path, _priority);
+
+    return promiseOrCallback(
+      this._database._native.setPriority(this.path, _priority),
+      onComplete,
+    );
   }
 
   /**
+   * Writes data the Database location. Like set() but also specifies the priority for that data.
    *
+   * @link https://firebase.google.com/docs/reference/js/firebase.database.Reference#setWithPriority
    * @param value
    * @param priority
-   * @returns {*}
+   * @param onComplete
+   * @returns {Promise}
    */
-  setWithPriority(value: any, priority: string | number | null) {
+  setWithPriority(value: any, priority: string | number | null, onComplete?: Function): Promise {
     const _value = this._serializeAnyType(value);
     const _priority = this._serializeAnyType(priority);
-    return this._database._native.setWithPriority(this.path, _value, _priority);
+
+    return promiseOrCallback(
+      this._database._native.setWithPriority(this.path, _value, _priority),
+      onComplete,
+    );
   }
 
   /**
+   * Writes multiple values to the Database at once.
    *
+   * @link https://firebase.google.com/docs/reference/js/firebase.database.Reference#update
    * @param val
-   * @returns {*}
+   * @param onComplete
+   * @returns {Promise}
    */
-  update(val: Object) {
+  update(val: Object, onComplete?: Function): Promise {
     const value = this._serializeObject(val);
-    return this._database._native.update(this.path, value);
+
+    return promiseOrCallback(
+      this._database._native.update(this.path, value),
+      onComplete,
+    );
   }
 
   /**
+   * Removes the data at this Database location.
    *
-   * @returns {*}
+   * @link https://firebase.google.com/docs/reference/js/firebase.database.Reference#remove
+   * @param onComplete
+   * @return {Promise}
    */
-  remove() {
-    return this._database._native.remove(this.path);
+  remove(onComplete?: Function): Promise {
+    return promiseOrCallback(
+      this._database._native.remove(this.path),
+      onComplete,
+    );
   }
 
   /**
    * Atomically modifies the data at this location.
-   * @url https://firebase.google.com/docs/reference/js/firebase.database.Reference#transaction
+   *
+   * @link https://firebase.google.com/docs/reference/js/firebase.database.Reference#transaction
    * @param transactionUpdate
    * @param onComplete
    * @param applyLocally
@@ -140,6 +180,7 @@ export default class Reference extends ReferenceBase {
       );
     }
 
+    // todo cleanup / use new promiseOrCallback logic
     return new Promise((resolve, reject) => {
       const onCompleteWrapper = (error, committed, snapshotData) => {
         if (error) {
@@ -190,7 +231,7 @@ export default class Reference extends ReferenceBase {
    * @param onComplete
    * @returns {*}
    */
-  push(value: any, onComplete: Function) {
+  push(value: any, onComplete?: Function) {
     if (value === null || value === undefined) {
       return new Reference(this._database, `${this.path}/${generatePushID(this._database.serverTimeOffset)}`);
     }
@@ -218,7 +259,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   orderByKey(): Reference {
-    return this.orderBy('orderByKey');
+    return this._query.orderBy('orderByKey');
   }
 
   /**
@@ -226,7 +267,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   orderByPriority(): Reference {
-    return this.orderBy('orderByPriority');
+    return this._query.orderBy('orderByPriority');
   }
 
   /**
@@ -234,7 +275,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   orderByValue(): Reference {
-    return this.orderBy('orderByValue');
+    return this._query.orderBy('orderByValue');
   }
 
   /**
@@ -243,7 +284,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   orderByChild(key: string): Reference {
-    return this.orderBy('orderByChild', key);
+    return this._query.orderBy('orderByChild', key);
   }
 
   /**
@@ -254,7 +295,7 @@ export default class Reference extends ReferenceBase {
    */
   orderBy(name: string, key?: string): Reference {
     const newRef = new Reference(this._database, this.path, this._query.getModifiers());
-    newRef.query.orderBy(name, key);
+    newRef._query.orderBy(name, key);
     return newRef;
   }
 
@@ -268,7 +309,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   limitToLast(limit: number): Reference {
-    return this.limit('limitToLast', limit);
+    return this._query.limit('limitToLast', limit);
   }
 
   /**
@@ -277,7 +318,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   limitToFirst(limit: number): Reference {
-    return this.limit('limitToFirst', limit);
+    return this._query.limit('limitToFirst', limit);
   }
 
   /**
@@ -288,7 +329,7 @@ export default class Reference extends ReferenceBase {
    */
   limit(name: string, limit: number): Reference {
     const newRef = new Reference(this._database, this.path, this._query.getModifiers());
-    newRef.query.limit(name, limit);
+    newRef._query.limit(name, limit);
     return newRef;
   }
 
@@ -303,7 +344,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   equalTo(value: any, key?: string): Reference {
-    return this.filter('equalTo', value, key);
+    return this._query.filter('equalTo', value, key);
   }
 
   /**
@@ -313,7 +354,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   endAt(value: any, key?: string): Reference {
-    return this.filter('endAt', value, key);
+    return this._query.filter('endAt', value, key);
   }
 
   /**
@@ -323,7 +364,7 @@ export default class Reference extends ReferenceBase {
    * @returns {Reference}
    */
   startAt(value: any, key?: string): Reference {
-    return this.filter('startAt', value, key);
+    return this._query.filter('startAt', value, key);
   }
 
   /**
@@ -335,7 +376,7 @@ export default class Reference extends ReferenceBase {
    */
   filter(name: string, value: any, key?: string): Reference {
     const newRef = new Reference(this._database, this.path, this._query.getModifiers());
-    newRef.query.filter(name, value, key);
+    newRef._query.filter(name, value, key);
     return newRef;
   }
 
@@ -679,7 +720,6 @@ export default class Reference extends ReferenceBase {
    * {@link https://firebase.google.com/docs/reference/js/firebase.database.Reference#off}
    */
   off(eventType?: string = '', originalCallback?: () => any) {
-    // TODO this.log.debug('ref.off(): ', this._refId, eventType);
     // $FlowFixMe
     const listeners: Array<DatabaseListener> = Object.values(this._refListeners);
     let listenersToRemove;
diff --git a/lib/utils/ReferenceBase.js b/lib/utils/ReferenceBase.js
index 5b0a655b..97fb64a6 100644
--- a/lib/utils/ReferenceBase.js
+++ b/lib/utils/ReferenceBase.js
@@ -7,8 +7,6 @@ export default class ReferenceBase {
     this.path = path || '/';
   }
 
-  // todo add missing firebase reference props/methods
-
   /**
    * The last part of a Reference's path (after the last '/')
    * The key of a root Reference is null.
diff --git a/lib/utils/index.js b/lib/utils/index.js
index 6a180bcb..488062d8 100644
--- a/lib/utils/index.js
+++ b/lib/utils/index.js
@@ -307,3 +307,29 @@ export function nativeWithApp(appName, NativeModule) {
   return native;
 }
 
+/**
+ * Return the existing promise if no callback provided or
+ * exec the promise and callback if optionalCallback is valid.
+ *
+ * @param promise
+ * @param optionalCallback
+ * @return {Promise}
+ */
+export function promiseOrCallback(promise: Promise, optionalCallback?: Function) {
+  if (!isFunction(optionalCallback)) return promise;
+
+  return promise.then((result) => {
+    // some of firebase internal tests & methods only check/return one arg
+    // see https://github.com/firebase/firebase-js-sdk/blob/master/src/utils/promise.ts#L62
+    if (optionalCallback.length === 1) {
+      optionalCallback(null);
+    } else {
+      optionalCallback(null, result);
+    }
+
+    return Promise.resolve(result);
+  }).catch((error) => {
+    optionalCallback(error);
+    return Promise.reject(error);
+  });
+}