Solved! Go to Solution.
You have 2 options
1) You can author a webmap on ArcGIS.com and add your shapefile feature service as a layer in that map. Then you can open the web map on iOS.
or
2) You can directly add the feature service as a feature layer (AGSFeatureLayer) to an AGSMapView component in your ios application. In this scenario, you're not opening a preconfigured web map but instead mashing up individual layers through code.