Follow these steps to cancel your subscription:

On iOS 12 or more recent:

  1. Open the App Store.
  2. Tap on the picture in the right-hand corner.
  3. Select "Manage Subscriptions".
  4. Choose Montessori Preschool and tap "Cancel subscription".

On any previous iOs:

  1. Open the Settings icon on your device (the grey one).
  2. Scroll down to iTunes & App Store.
  3. Select our iTunes ID or login.
  4. Enter your password.
  5. Scroll down to "Subscriptions".
  6. Find Montessori Preschool.
  7. Tap "Cancel subscription"

The official Apple step-by-step is available here.