// First time activity
        mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
        Boolean welcomeScreenShown = mPrefs.getBoolean(welcomeScreenShownPref, false);

        if (!welcomeScreenShown) {
            // Welcome
            Intent intent = new Intent(YourMainActivity.this, WelcomeTutorialActivity.class);
            startActivity(intent);
            // Shared Preferences
            SharedPreferences.Editor editor = mPrefs.edit();
            editor.putBoolean(welcomeScreenShownPref, true);
            editor.commit(); // Very important to save the preference
        }