Crush Them All is free to play, but you can buy in-game currency that helps you progress faster. This in-game currency is purchased with real money using the iTunes store.
To control the levels of security for each step of the purchasing process, enter your device's Settings > General > Restrictions.
In the Restrictions menu, you can enable or disable restrictions. If you wish to enable them, the system will require that you enter your passcode.
After the restrictions are enabled, scroll down to "In-App Purchases". Here, you can choose to
• completely disable every in-app purchase (turn the settings to OFF).
• manage the frequency of the password request using the "Require Password" button.
If you’d like to continue making in-app purchases, you can set the device to require your password every time you make a purchase (select “Immediately”) or every fifteen minutes.