Football tap

The project I have in mind, is a simple type Iphone app. The game involves a football and requires the user to tap the screen to keep it up (juggling the ball). I would however like to add some extras into it, to make it more appealing. A currency type system where after each round/game the player receives x amount of coins, which can later be used to buy different types of skins/backgrounds and even a couple abilities such as extra life and so on. On top of this, I would the game to have a high scoring system and facebook integration, giving the game a multi player feel. Finally I would like two versions of the game. A free and a paid. The free version will basically be the full game, but the user will not be able to access certain parts of it.