The basic version of this application is free and can be used for limited days of trial.
The application shows a reminder on how many days of trial remaining.
After the trial period is over, you can still use the application but you will no longer be able to reach higher levels.
With an annual subscription you can unlock unlimited levels.
The annual subscription price may vary by location. Subscriptions will be charged to your credit card through your iTunes account. Your subscription will automatically renew unless canceled at least 24 hours before the end of the current period. You will not be able to cancel the subscription once activated. You may cancel automatic renewal by selecting Manage App Subscriptions in your iTunes Account settings and selecting the subscription you want to modify.