[Galaxy S II Themes and Apps] gerryS2:
In DisplaySettings.smali I have found some feature but this feature (QuickLaunch) work with a small edit in statusbar file

For this guide is necessary:

-SecSettings;

-SystemUI;

-Notepad++;

-apktool for decompile and compile this file.

For SecSettings:

1.Decompile SecSettings and go to smali/com/android/settings and open DisplaySettings.smali

2.Search this line: quick_launch

3.And now remove this line in .method public onCreate(Landroid/os/Bundle;)V:

:cond_a
const-string v11, "quick_launch"

invoke-virtual {p0, v11}, Lcom/android/settings/DisplaySettings;->findPreference(Ljava/lang/CharSequence;)Landroid/preference/Preference;

move-result-object v11

check-cast v11, Landroid/preference/ListPreference;

iput-object v11, p0, Lcom/android/settings/DisplaySettings;->mQuickLaunchPreference:Landroid/preference/ListPreference;

const-string v11, "quick_launch_app"

const/4 v12, 0x0

invoke-static {v8, v11, v12}, Landroid/provider/Settings$System;->getInt(Landroid/content/ContentResolver;Ljava/lang/String;I)I

move-result v2

iget-object v11, p0, Lcom/android/settings/DisplaySettings;->mQuickLaunchPreference:Landroid/preference/ListPreference;

invoke-static {v2}, Ljava/lang/String;->valueOf(I)Ljava/lang/String;

move-result-object v12

invoke-virtual {v11, v12}, Landroid/preference/ListPreference;->setValue(Ljava/lang/String;)V

iget-object v11, p0, Lcom/android/settings/DisplaySettings;->mQuickLaunchPreference:Landroid/preference/ListPreference;

invoke-virtual {v11, p0}, Landroid/preference/ListPreference;->setOnPreferenceChangeListener(Landroid/preference/Preference$OnPreferenceChangeListener;)V

const/4 v1, 0x1

:try_start_0
const-string v11, "window"

invoke-static {v11}, Landroid/os/ServiceManager;->getService(Ljava/lang/String;)Landroid/os/IBinder;

move-result-object v11

invoke-static {v11}, Landroid/view/IWindowManager$Stub;->asInterface(Landroid/os/IBinder;)Landroid/view/IWindowManager;

move-result-object v10

invoke-interface {v10}, Landroid/view/IWindowManager;->hasSystemNavBar()Z
:try_end_0
.catch Landroid/os/RemoteException; {:try_start_0 .. :try_end_0} :catch_1

move-result v11

if-nez v11, :cond_11

const/4 v1, 0x1

:goto_2
invoke-virtual {p0}, Lcom/android/settings/DisplaySettings;->getActivity()Landroid/app/Activity;

move-result-object v11

invoke-static {v11}, Lcom/android/settings/Utils;->isTablet(Landroid/content/Context;)Z

move-result v11

if-eqz v11, :cond_b (REMOVE THIS LINE)

if-eqz v1, :cond_c

:cond_b (REMOVE THIS LINE)
invoke-virtual {p0}, Lcom/android/settings/DisplaySettings;->getPreferenceScreen()Landroid/preference/PreferenceScreen; (REMOVE)

move-result-object v11 (REMOVE THIS LINE)

iget-object v12, p0, Lcom/android/settings/DisplaySettings;->mQuickLaunchPreference:Landroid/preference/ListPreference; (REMOVE)

invoke-virtual {v11, v12}, Landroid/preference/PreferenceScreen;->removePreference(Landroid/preference/Preference;)Z (REMOVE THIS LINE)

When you have remove this lines, you can compile this file.

For SystemUI:

Decompile SystemUI and go to res/layout/ and open this file:

tw_status_bar_expanded if you want insert this button under brightness slider in notification panel

tw_status_bar_expanded_header if you want insert this button next to date view in notification panel

For tw_status_bar_expanded add this line:

<LinearLayout android:orientation="vertical" android:id="@id/brightness_controller" android:background="#ff000000" android:layout_width="fill_parent" android:layout_height="56.0dip">
<LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="55.0dip">
<ImageView android:id="@id/brightness_icon" android:clickable="true" android:layout_width="25.0dip" android:layout_height="fill_parent" android:layout_marginLeft="13.0dip" android:src="@drawable/ic_sysbar_brightness" android:contentDescription="@string/accessibility_brightness_icon" />
<FrameLayout android:id="@id/brightness_group" android:layout_width="fill_parent" android:layout_height="fill_parent">
<com.android.systemui.statusbar.policy.ToggleSlider android:id="@id/brightness" android:layout_width="fill_parent" android:layout_height="fill_parent" systemui:text="@string/status_bar_settings_auto_brightness_label" />
<com.android.systemui.statusbar.policy.ToggleSlider android:id="@id/auto_brightness" android:layout_width="fill_parent" android:layout_height="fill_parent" systemui:text="@string/status_bar_settings_auto_brightness_label" />
</FrameLayout>
</LinearLayout>
<View android:background="#ff091a24" android:layout_width="fill_parent" android:layout_height="1.0dip" />
</LinearLayout> UNDER THIS LINE INSERT THIS:
<com.android.systemui.statusbar.policy.QuickLaunchKeyButtonView android:id="@id/quick_launch" android:visibility="visible" android:layout_width="wrap_content" android:layout_height="fill_parent" android:src="@drawable/tw_ic_sysbar_capture" android:contentDescription="@string/accessibility_capture" />

For tw_status_bar_expanded_header:

<Space android:layout_width="0.0dip" android:layout_height="0.0dip" android:layout_weight="1.0" /> UNDER THIS LINE INSERT:
<com.android.systemui.statusbar.policy.QuickLaunchKeyButtonView android:id="@id/quick_launch" android:visibility="visible" android:layout_width="wrap_content" android:layout_height="fill_parent" android:src="@drawable/tw_ic_sysbar_capture" android:contentDescription="@string/accessibility_capture" />