Well, it’s been three-and-a-half years, but I’ve finally got around to getting to a point of writing an iOS app. I wouldn’t hold your breath waiting to get a copy, though – it’s purely for my private use, to aid in monitoring and administering the IES project.
After doing enough tutorials and similar exercises to be comfortable in building the app and the UI, I got around to trying calls to the AWS infrastructure. This proved a bit more difficult than I anticipated – hence this aide-mémoire. This isn’t going to be useful for non-iOS developers, and I doubt it’s going to have anything new for more seasoned iOS developer; only iOS noobs like me need bother.