How to launch android wear activity from mobile

I have been working on a project where I need a button on a mobile to start up an activity on the watch. I have been going through the data layer sample in the sdk but can not get it working. I set up a wearable listener service class, but it is not picking up any messages. The service is added to the manifest but it is still not working. I do have other services too and I am thinking I might have too many services.

On the Wear watch, does an activity have to be running in order for it to start another activity? I want the watch to run nothing until it receives a message, is this possible?

Also, what should my edit configuration settings for wear module be? (eg, do not launch activity, launch default or launch from activity) I just want the wearable to boot up when a message is received.

If anybody can point me in the right direction, it would be hugely appreciated.

Thanks.