The new LG Watch Urbane 2nd Edition LTE is the first watch to run Android 6.0 Marshmallow (API 23) for Android Wear. Currently, all other Android Wear watches implement API 22, and in the coming months, these will receive an OTA update for API 23 as well.
So what does this mean for you as an Android Wear developer? You will need to ensure that your apps are compatible with both API 23 and API 22 watches. While you can start implementing the new features in this post, you still need to maintain backwards compatibility until all watches are upgraded.
New permissions model and samples
API 23 introduces a new runtime permissions model for both phones and watches. The new permissions model allows users to pick and choose which permissions to grant apps at the time of use. In addition, new permissions settings allow users to turn on and off app permissions at any time.
To use the new permissions model on Wear, read Permissions on Android Wear. This training guide provides an in-depth discussion of Wear-specific scenarios, such as when your Wear app relies on a phone-side permission. In addition, all of the Android Wear samples have been updated to use the new permissions model, and a new RuntimePermissionsWear sample shows how to handle permission requests across devices.
When you are ready, you can update your application on both the phone and watch side to use compileSdkVersion 23 and targetSdkVersion 23. Make sure that you check and request the permissions needed by your app at runtime, on both the phone and the watch. It is important that you do not change targetSdkVersion to 23 until you have implemented the permission checks properly, since it changes how the system installs and runs the app. For example, an API call that might have previously returned a result could now fail, causing the app to behave in unexpected ways.
Source: Android Developers Blog
