APK file naming. Put in base directory of the project and add 'apply from: 'artifacts.gradle'' to the apps build.gradle. All credit goes to Erik Ogenvik at Jayway for his blog post http://www.jayway.com/2015/03/13/producing-better-named-android-apks-with-gradle/

artifacts.gradle

android.applicationVariants.all { variant ->
    def appName
    //Check if an applicationName property is supplied; if not use the name of the parent project.
    if (project.hasProperty("applicationName")) {
        appName = applicationName
    } else {
        appName = parent.name
    }

    variant.outputs.each {output ->
        def newApkName
        //If there's no ZipAlign task it means that our artifact will be unaligned and we need to mark it as such.
        if (output.zipAlign) {
            newApkName = "${appName}-${output.baseName}-${variant.versionCode}.apk"
        } else {
            newApkName = "${appName}-${output.baseName}-${variant.versionCode}-unaligned.apk"
        }
        output.outputFile = new File(output.outputFile.parent, newApkName)
    }
}