Sometimes, most of the time when my LG G watch closes the app automatically by going to sleep/dim mode, if I open the app again by going to the start menu there are two instanc
Have you looked at the android:launchMode attribute in the AndroidManifest.xml for the activity?
android:launchMode
AndroidManifest.xml
perhaps android:launchMode="singleInstance" will help you out.
android:launchMode="singleInstance"
http://developer.android.com/guide/topics/manifest/activity-element.html#lmode