Setting access levels

Saving best score only when current is bigger

Changing button positions

Readme changes

Moved static keys to separated files

Audio in loop

Moving next tetromino view login to another view controller

Store some variables persistently

Making tests green again

Implementing Next Tetromino

New background, icon and play stop and game over implementation

Added a grid, new colours and some design changes

Updating current score label

Applying View Controller Containment to encapsulate Board View logic

Adding repeated action when button is held