Thanks Suganya,
So based on your "offline" answer, it sounds like I could possibly create an app like this without ArcGIS Server or ArcGIS online right? If I just had the offline gas station buffers (using the arcgis runtime sdk) and used a method to determine of the users current location intersected the buffers, then I could pop up an alert to the user, etc. Yes, I would also definitely need to join apple developers group to publish any app properly. If I'm incorrect about anything I just stated above, please let me know.
Many thanks.