The only data used by app is text information from pasteboard (text data which was copied the last time). This data is used to provide additional functionalities. If you want to prevent app from using even this one, you can not to enable Full Access in keyboard settings.
App comes with functionality which lets you to share your thoughts through Facebook or Twitter, but again no data is gathered.

No data is retained or distributed to servers. User is 100% secure from data flow as keyboard extension doesn’t use internet connection.

App is rated 4+ and there are no additional obligations for the children under the age of 13.

App and the keyboard custom extension have access to user’s speaker to choose and play key click sounds. This can be disabled from app settings or non-accessible by disabling Full Access in keyboard settings.