After installation, you will need to create a new custom channel field and assign that field to 1 or more of your channels in which you would like to use Reading Time Pro. When creating a new custom field you will see Reading Time Pro as an available fieldtype option. You can name this custom field anything you want, but we suggest calling it reading_time.
There are no settings for this field type. After assigning the field to a channel you will be able to see the field in the Publish page when viewing an entry in that channel. The field display in the control panel has no inputs. It will simply display This entry can be read [insert time here] or Reading time has not been calculated.