Run while screen sleeps

Unity Engine
,
1

is there anyway i can keep my apk running when the screen goes off?

2

It should already.

What does your manifest file look like?

3 
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:installLocation="preferExternal" package="com.ant.Cell" android:versionName="1.0" android:versionCode="1">
  <supports-screens android:smallScreens="true" android:normalScreens="true" android:largeScreens="true" android:xlargeScreens="true" android:anyDensity="true" />
  <application android:icon="@drawable/app_icon" android:label="@string/app_name" android:debuggable="false">
    <activity android:name="com.unity3d.player.UnityPlayerActivity" android:label="@string/app_name" android:configChanges="keyboardHidden|orientation" android:screenOrientation="landscape">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <activity android:name="com.unity3d.player.VideoPlayer" android:label="@string/app_name" android:configChanges="keyboardHidden|orientation">
    </activity>
  </application>
  <uses-feature android:glEsVersion="0x00020000" />
  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
  <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="12" />
</manifest>
4

Looks like this can only be done with a plugin to inform Android to regard my app as a Service.
I tried adding android: persistent=“true”, but it did nothing.