A small collaborative game where players work to complete a jigsaw puzzle.
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.


Realm Puzzle

A Collaborative Puzzle Game, powered by the Realm Platform

This app is a simple implementation of a team game. Multiple players simultaneously work together to solve a jigsaw puzzle on a shared canvas. Whenever one player moves a piece, all players see the piece move in real-time.

Realm Puzzle

CI Status GitHub license


  • Allows users to collaborate in solving a jigsaw puzzle together.
  • Puzzle can be reset by tapping the screen with 3 fingers, 3 times.
  • Can connect to any running instance of Realm Object Server


  • iOS 9.0 and above
  • Xcode 8.3
  • Realm Plaform / Realm Object Server 2.x

Realm Platform

This application demonstrates features of the Realm Platform and needs to have a working instance of the Realm Object Server version 2.x to make data available between instances of the Puzzle app. The Realm Object Server can be installed via npm as a node application for macOS or Linux. Please see the installation instructions. If you already got Node.js installed, it's a one-liner.

Realm Studio

Another useful tool is Realm Studio which is available for macOS, Linux and Windows and allow developers to inspect and manage Realms and the Realm Object Server. Realm Studio is recommended for all developers and can be downloaded from the Realm web site.


CocoaPods is required in order to install all of the third party dependencies (such as Realm itself) into Realm Puzzle.

  1. If you haven't already, install CocoaPods.
  2. Open Terminal, and navigate to the root Realm Puzzle directory, e.g. cd ~/Projects/realm-puzzle.
  3. Run pod install to install the necessary dependencies needed by Realm Puzzle.
  4. Open RealmPuzzle.xcworkspace instead of the xcproject file.

Connecting to the Realm Object Server

When launching the app each time, you'll be presented with a login form in order to connect to the right Realm Object Server instance.

Realm Puzzle

For the server URL field, you may simply enter localhost if you're running out of the iOS Simulator with the Realm Object Server at the same time. For iOS devices running on the same network as that Mac, you can alt-click on the Wi-Fi icon in the macOS status bar to get the Mac's local IP address. You can then manually enter this into the server URL field on the iOS device.

You'll be required to create an admin account the first time you run an instance of the Realm Object Server. You may use this account when logging into Realm Puzzle by entering in the same username/password pair. Alternatively, you may also register new user accounts from the form by tapping the 'Register a new account' button.

App Architecture

The data model behind Realm Puzzle is quite simple. There are 2 Realm object subclasses: RLMPuzzle and RLMPuzzlePiece.

@interface RLMPuzzle : RLMObject

@property NSInteger uuid;
@property RLMArray<RLMPuzzlePiece> *pieces;



@interface RLMPuzzlePiece : RLMObject

@property NSInteger identifier;
@property double x;
@property double y;



RLMPuzzle represents a discrete puzzle session, and contains a list of puzzle piece objects. RLMPuzzlePiece represents a single puzzle piece on the board, and holds the X and Y coordinates of its position on the board.

Upon launching for the first time and starting a new session, a RLMPuzzle object is created. After that, 16 Realm RLMPuzzle instances, one representing each piece on the board are created and saved to Realm. These objects only store the ID reference of the puzzle piece they represent (Referenced in an enum), and the XY coordinate of the puzzle piece.

Whenever the user taps and drags a puzzle piece, for each frame of movement, a Realm write transaction is performed that writes the new XY coordinate to the Realm file.

These new coordinates are then synchronized via the Realm Mobile Platform. A global RLMRealm change notification block is registered, and whenever a change occurs, all puzzle pieces positions are refreshed.

Third Party Dependencies

The following modules will be installed as part of the CocoaPods installation:


See CONTRIBUTING.md for more details!

This project adheres to the Contributor Covenant Code of Conduct. By participating, you are expected to uphold this code. Please report unacceptable behavior to info@realm.io.


Distributed under the MIT license. See LICENSE for more information.