Need a Save Me button added

I bought this template - http://www.tandgapps.co.uk/shop/tenten/

 

and would like to add a small feature to it.

 

Basically what I want is when you play the game and either loose or pause the game, I want a “Save Me” button which would have like 3 credits for a start.

 

So when you use the button, it saves your current score and allows you start the game with the saved score and not zero.

 

This template comes with a SQL database but would prefer this new feature added using json file as separate to avoid any update issue with existing downloads.