How to start activity through my app in another app?

Question

I am very new to writing android app, I am trying to start specific activity from an other app (App B)through my app (App A). I know how to launch the App B but I need App B do some specific task with a click of button without showing the launching process I just want to jump to that task(like playing music with out showing the introduction and starting part of App B).

This is part of App A , the place I want to do specific task from App B instead of just launching it. ( even maybe I don't need to launch it )

public void playOn(View view) {

        ImageButton sound = (ImageButton) findViewById(R.id.musicButton);
        if (lightt) {
            sound.setImageResource(R.drawable.play_dn);
            lightt = false;
        } else {
            sound.setImageResource(R.drawable.play_up);
           lightt = true;
        }

       Intent intent = getPackageManager().getLaunchIntentForPackage("com.Zample.RUNiBplayMusic");


        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }

and this is part of App B that I have access to

<application android:icon="@drawable/ic_launcher" android:label="Bplay Music" android:name="com.Zample.RUNiBplayMusic.Common.App" android:theme="@style/AppTheme">
        <activity android:launchMode="singleTask" android:name=".StartActivity" android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.VIEW"/>
                <category android:name="android.intent.category.DEFAULT"/>
                <category android:name="android.intent.category.BROWSABLE"/>
                <data android:host="com.bplaymusicwifi" android:scheme="bplaymu"/>
            </intent-filter>
        </activity>
        <activity android:finishOnTaskLaunch="true" android:name=".HelpListActivity" android:screenOrientation="portrait"/>
        <activity android:launchMode="singleTask" android:name=".DeviceListActivity" android:screenOrientation="portrait"/>
        <activity android:finishOnTaskLaunch="true" android:name=".PlayModeActivity" android:screenOrientation="portrait"/>
        <activity android:finishOnTaskLaunch="true" android:name=".HelpListActivity" android:screenOrientation="portrait"/>
        <receiver android:label="Bplay Music" android:name=".AppWidget.AppWidgetSmall">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
            </intent-filter>
        <receiver android:label="Bplay Music" android:name=".AppWidget.AppWidgetBig">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
            </intent-filter>
            <meta-data android:name="android.appwidget.provider" android:resource="@xml/widget_info_big"/>
        </receiver>
        <service android:name=".AppWidget.Bplay MusicService"/>
        <service android:name=".Record.RecordService"/>
    </application>

I think this part of the code from App B might help me. but I am not sure.
I hope you can help me how to solve this issue.