Besides a header TextItem, a DistanceGroup shows a distance value in double and a unit value. You can use DistanceGroup when you would allow user to modify either the distance value or distance unit. When the distance value is tapped, the application will navigate user to a new Dialog with a numeric keypad where a new value can be entered. When the distance unit is tapped, application will show a new Dialog with a collection of pre-defined distance units to choose from. User can accept or cancel the new value before they leave the Dialog.

DistanceGroup is designed to be used with a GroupView control. Normally you createa new instance of DistanceGroup, and add it to a GroupView control.

There are other types of Groups that are designed to work with different types of data you can show or edit, including DateAttributeGroup, EnumAttributeGroup, NumericAttributeGroup, RadioGroup, SelectionGroup, StringAttributeGroup, etc.

If you want to show user a read-only group, use ReadOnlyAttributeGroup.

System.Object
   ESRI.ArcGIS.Mobile.Client.Controls.Groups.Group
      ESRI.ArcGIS.Mobile.Client.Controls.Groups.DistanceGroup

Reference