Detect if app is installed on Android

We are developing a Unity application which needs to check if certain apps are already installed or not on the device. We managed to do this easily on iOS using PlayerPrefs and Xcode, but we don’t know how to do the same on Android.
There are lots of questions like this on the web but no one applies dircetly to Unity, so we are in need for some help or hints. Thanks!

public bool IsAppInstalled(string bundleID){
AndroidJavaClass up = new AndroidJavaClass(“com.unity3d.player.UnityPlayer”);
AndroidJavaObject ca = up.GetStatic(“currentActivity”);
AndroidJavaObject packageManager = ca.Call(“getPackageManager”);
Debug.Log(" ********LaunchOtherApp ");
AndroidJavaObject launchIntent = null;
//if the app is installed, no errors. Else, doesn’t get past next line
launchIntent = packageManager.Call(“getLaunchIntentForPackage”,bundleID);
// ca.Call(“startActivity”,launchIntent);
}catch(Exception ex){
if(launchIntent == null)
return false;
return true;
return false;