Refactored some code
Create methods to save game state to string or a bytearray
Added callbacks through a listener to the GamePlayFragment and saved the game state when the game is interrupted
Created a file for handling the invites through the inbox
Created a file for handling a game game via inviting a player
Extract methods to select players to MultiplayerGamePlaySelectionActivity
Implement inbox to select existing matches or invites
Add a item to the main menu to select an existing match
Save and retrieve a game status via play services for multiplayer
Refactored activity MultiplayerGameFinished to a fragment
Refactored saving the different game states to Play Services.

For two players there are three game states: original game (starting positions), game for player 1 and the game for player 2.
Fix bug with setting the original game for player 2
Created fragment layout for when the player has finished the puzzle in multiplayer
Created the row with for a player in the finish screen for a multiplayer match

This row is showing the player's picture, name and the score. For players who did not finish a turn yet: it is showing a dash
Created a task to download images in the background
Created a simple finish screen for when a the player finished a turn.
Created checks for status codes