Me and my husband had been developing our own Android apps published to Google Play for a while and never made much money. But when Android Wear first came out, we started developing watch faces (mostly ones we wanted for ourselves) and persistence finally paid off. Income varies, but we've been steadily making between $500 and $1500/month. These are the top two: https://play.google.com/store/apps/details?id=com.sparkistic... and https://play.google.com/store/apps/details?id=com.sparkistic...