I have used message api to send messages between multiple android smart watches and a smart phone. I have used wearable listener service to launch the app in phone when the app in smart watch is launched. I have also used capability api to selectively send messages to the connected devices.
Recently, I have come across put data map request to sync data between the devices. I also feel there are more uses and functionalities for these APIs and services.
I would like to know in detail what are message api, wearable listener service, put data map request, capability api etc used for. When should we consider these to use? What are their key functions and advantages? I know my question is broad and any links to read about them would be highly appreciated.