In order to cancel a pending Private Group invite, or delete any other invitation from the list of users in your Private Group from an iPhone with Glympse:
1. Open the navigation menu in the upper left corner.
2. Select the private group.
3. Click the group options button in the upper corner.
4. Scroll down to view the invites, and slide left on the invite you would like to delete or cancel. Click on Remove.
5. The user will no longer be able to access the Private Group.