IntentServiceでToastを使うと消えなくなる問題に対処する ref: http://qiita.com/gam0022/items/56475779c598c6e8b073

file0.java

public class DisplayToast implements Runnable {
  private final Context mContext;
  String mText;

  public DisplayToast(Context mContext, String text){
    this.mContext = mContext;
    mText = text;
  }

  public void run(){
    Toast.makeText(mContext, mText, Toast.LENGTH_SHORT).show();
  }
}

file1.java

public class MyService extends IntentService {
  Handler mHandler;

  public MyService(){
    super("MyService");
    mHandler = new Handler();
  }

  @Override
    protected void onHandleIntent(Intent intent) {
      mHandler.post(new DisplayToast(this, "Hello World!"));

    }   
}