The client field can be added by following these steps:
  1. Access the TMM Store, scroll down to the "Bundles" section and click the "Ultimate" row. Details about the purchase along with screenshots will be provided on the right side of the screen. When you are ready to purchase, click the "Buy" button in the upper right corner of the screen and follow the In-App purchase instruction provided by Apple to complete the purchase. Buying this feature will also allow you to group/sort the trips by client.