To activate your free 7 day trial:

1. Install the free app.
2. Rotate to System. Show Me
3. Tap the Shopping Cart on the left.
4. Subscribe to the option of your choice.  You will not be charged until the end of the trial period. If you cancel your subscription at any time during the trial period you won’t be charged.
5. If you have an active subscription you can view, change, or cancel it anytime:
   1. From the shop page tap Manage Subscriptions.
   2. From Apple App store or iTunes.