I've managed to get the lesson data populated as described (thanks, the documentation was pretty clear, although the Objective-C version still shows swift code).
When I swap to student mode, and relaunch the Schoolwork app, I can then double tap on the activity and it launches my app quite happily.
What I haven't found described so far, is how my app determines what activity or CLSContext was requested so that I can direct the student into the requested content automatically.
I'm guessing I can find it in the "launchOptions" dictionary provided to:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions;
Any help would be appreciated.