How does one label a feature layer?

[SeanNakasone]

How does one label a feature layer?
We have a Feature class with a circular pole symbol.  Next to the pole, we want to show the pole number as a label.
The label shows automatically with a Map Service, but not with a Feature Service.  I looked at AGSFeatureLayer's labelingInfo property but it's readonly.

[RickJones]

We use separate Dynamic label layers so we can turn them off in the legend.

[SeanNakasone]

Thanks for the info.  Yes, we have tried a separate feature layer from a dynamic map service too, and labeling does work for us.  But we are investigating our offline options.  So I tried to use an Annotation Feature Class, but when doing an analyze, I get this warning Code=24035 Description="Annotation Layer type is not supported for Feature Service".  And to confirm that warning, the annotations don't show on the iOS device as a feature layer.  So does anyone know how to get text displayed on an iOS device offline?  Does anyone know if this is possible or impossible?