[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] loserskater:
This will allow you to enable and disable the brightness slider right from the settings menu.

No more flashing extra zips, or having to build another SystemUI!

Let's get to it!

The two files we'll be working with are:

SecSettings.apk

SystemUI.apk

First let's start with SecSettings.apk

Navigate to res/values/string.xml

And add the following lines to the bottom:

<string name="brightness_slider_title">Display brightness slider</string>
<string name="brightness_slider_summary">Show brightness slider in notification panel</string>

Next navigate to res/xml/display_settings.xml

Add the line in red:

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen android:title="@string/display_settings"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:settings="http://schemas.android.com/apk/res/com.android.settings">
<PreferenceCategory android:title="@string/tts_general_section_title" />
<PreferenceScreen android:title="@string/wallpaper" android:key="wallpaper" android:fragment="com.android.settings.WallpaperSettings" />
<PreferenceScreen android:title="@string/led_indicator_settings" android:key="led_indicator_settings" android:fragment="com.android.settings.LedIndicatorSettings" />
<SwitchPreferenceScreen android:title="@string/page_buddy" android:key="contextualpage_settings" android:summary="@string/page_buddy_summary" android:fragment="com.android.settings.ContextualPageSettings" />
<PreferenceCategory android:title="@string/display_label" android:key="screen_category" />
<PreferenceScreen android:title="@string/screen_mode_setting" android:key="mode" android:summary="@string/screen_mode_summary">
<intent android:targetPackage="com.android.settings" android:action="android.intent.action.MAIN" android:targetClass="com.android.settings.ModePreview" />
</PreferenceScreen>
<com.android.settings.BrightnessPreference android:title="@string/brightness" android:key="brightness" android:widgetLayout="@layout/round_more_icon" android:dialogTitle="@string/brightness" />
<CheckBoxPreference android:title="@string/accelerometer_title_second" android:key="accelerometer_second" />
<CheckBoxPreference android:title="@string/accelerometer_title" android:key="accelerometer" />
<ListPreference android:persistent="false" android:entries="@array/screen_timeout_entries" android:title="@string/screen_timeout" android:key="screen_timeout" android:summary="@string/screen_timeout_summary" android:widgetLayout="@layout/round_more_icon" android:entryValues="@array/screen_timeout_values" />
<PreferenceScreen android:title="@string/screensaver_settings_title" android:key="screensaver" android:fragment="com.android.settings.DreamSettings" />
[COLOR="Red"]<CheckBoxPreference android:title="@string/brightness_slider_title" android:key="display_brightness_slider" android:summary="@string/brightness_slider_summary" />[/COLOR]
<PreferenceCategory android:title="@string/features_category_title" android:key="features_category" />
<CheckBoxPreference android:title="@string/intelligent_rotation_title" android:key="intelligent_rotation" android:summary="@string/intelligent_rotation_summary" />
<CheckBoxPreference android:title="@string/intelligent_sleep_title" android:key="intelligent_sleep" android:summary="@string/intelligent_sleep_summary" />
<PreferenceCategory android:title="@string/font" />
<com.android.settings.flipfont.FontListPreference android:title="@string/monotype_preference_title" android:key="MONOTYPE" android:summary="@string/monotype_preference_summary" android:widgetLayout="@layout/round_more_icon" />
<com.android.settings.FontSizeListPreference android:entries="@array/entries_font_size" android:title="@string/title_font_size" android:key="font_size" android:summary="@string/summary_font_size" android:widgetLayout="@layout/round_more_icon" android:dialogTitle="@string/dialog_title_font_size" android:entryValues="@array/entryvalues_font_size" />
<PreferenceCategory android:title="@string/more_settings" android:key="more_settings" />
<ListPreference android:persistent="false" android:entries="@array/quick_launch_entries" android:title="@string/quick_launch_title" android:key="quick_launch" android:summary="@string/screen_quick_launch_summary" android:widgetLayout="@layout/round_more_icon" android:entryValues="@array/quick_launch_values" />
<CheckBoxPreference android:title="@string/sub_lcd_auto_lock" android:key="sub_lcd_auto_lock" android:summary="@string/sub_lcd_auto_lock_summary" />
<CheckBoxPreference android:title="@string/key_night_mode" android:key="key_night_mode" />
<ListPreference android:persistent="false" android:entries="@array/key_backlight_entries" android:title="@string/key_backlight" android:key="key_backlight" android:widgetLayout="@layout/round_more_icon" android:entryValues="@array/key_backlight_values" />
<ListPreference android:persistent="false" android:entries="@array/touch_key_light_entries" android:title="@string/touch_key_light" android:key="touch_key_light" android:summary="@string/touch_key_light_summary" android:widgetLayout="@layout/round_more_icon" android:entryValues="@array/touch_key_light_values" />
<CheckBoxPreference android:persistent="false" android:title="@string/display_battery_percentage" android:key="display_battery_level" android:summary="@string/display_battery_percentage_summary" />
<CheckBoxPreference android:persistent="false" android:title="@string/display_saving" android:key="power_saving_mode" android:summary="@string/display_saving_mode_summary" />
<CheckBoxPreference android:persistent="false" android:title="@string/notification_pulse_title" android:key="notification_pulse" />
<CheckBoxPreference android:title="@string/edgezoom_title" android:key="edgezoom_toggle" android:summary="@string/edgezoom_summary" />
</PreferenceScreen>

Next navigate to smali/com/android/settings/DisplaySettings.smali

Add the following in red:

.field private mBrightness:Lcom/android/settings/BrightnessPreference;

.field private mBrightnessPreference:Lcom/android/settings/BrightnessPreference;

[COLOR="red"].field private mBrightnessSliderPreference:Landroid/preference/CheckBoxPreference;[/COLOR]

.field private mContextualPage:Landroid/preference/SwitchPreferenceScreen;

.field protected mContextualPageUncheckerHandler:Landroid/os/Handler;

.method private updateState

Add the sections in red

iget-object v3, p0, Lcom/android/settings/DisplaySettings;->mDisplayBatteryLevel:Landroid/preference/CheckBoxPreference;

invoke-virtual {p0}, Lcom/android/settings/DisplaySettings;->getContentResolver()Landroid/content/ContentResolver;

move-result-object v0

const-string v4, "display_battery_percentage"

invoke-static {v0, v4, v2}, Landroid/provider/Settings$System;->getInt(Landroid/content/ContentResolver;Ljava/lang/String;I)I

move-result v0

if-eqz v0, :cond_3

move v0, v1

:goto_2
invoke-virtual {v3, v0}, Landroid/preference/CheckBoxPreference;->setChecked(Z)V

[COLOR="red"]iget-object v3, p0, Lcom/android/settings/DisplaySettings;->mBrightnessSliderPreference:Landroid/preference/CheckBoxPreference;

invoke-virtual {p0}, Lcom/android/settings/DisplaySettings;->getContentResolver()Landroid/content/ContentResolver;

move-result-object v0

const-string v4, "display_brightness_slider"

invoke-static {v0, v4, v2}, Landroid/provider/Settings$System;->getInt(Landroid/content/ContentResolver;Ljava/lang/String;I)I

move-result v0

if-eqz v0, :cond_bs

move v0, v1

:goto_bs
invoke-virtual {v3, v0}, Landroid/preference/CheckBoxPreference;->setChecked(Z)V[/COLOR]

.line 807
iget-object v0, p0, Lcom/android/settings/DisplaySettings;->mTouchKeyLight:Landroid/preference/ListPreference;

invoke-virtual {p0}, Lcom/android/settings/DisplaySettings;->getContentResolver()Landroid/content/ContentResolver;

move-result-object v3

const-string v4, "button_key_light"

const/16 v5, 0x5dc

invoke-static {v3, v4, v5}, Landroid/provider/Settings$System;->getInt(Landroid/content/ContentResolver;Ljava/lang/String;I)I

move-result v3

invoke-static {v3}, Ljava/lang/String;->valueOf(I)Ljava/lang/String;

move-result-object v3

invoke-virtual {v0, v3}, Landroid/preference/ListPreference;->setValue(Ljava/lang/String;)V

:cond_2
move v0, v2

.line 802
goto :goto_1

:cond_3
move v0, v2

.line 805
goto :goto_2

[COLOR="red"]:cond_bs
move v0, v2

goto :goto_bs[/COLOR]

:cond_4
move v0, v2

.line 811
goto :goto_3

:cond_5
move v1, v2

.line 812
goto :goto_4
.end method

.method public onCreate

Add the parts in red:

const-string v11, "display_battery_level"

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

move-result-object v11

check-cast v11, Landroid/preference/CheckBoxPreference;

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

[COLOR="red"]const-string v11, "display_brightness_slider"

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

move-result-object v11

check-cast v11, Landroid/preference/CheckBoxPreference;

iput-object v11, p0, Lcom/android/settings/DisplaySettings;->mBrightnessSliderPreference:Landroid/preference/CheckBoxPreference;[/COLOR]

.line 398
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_6

.method public onPreferenceTreeClick

Add the parts in red

:cond_4
iget-object v0, p0, Lcom/android/settings/DisplaySettings;->mDisplayBatteryLevel:Landroid/preference/CheckBoxPreference;

invoke-virtual {p2, v0}, Ljava/lang/Object;->equals(Ljava/lang/Object;)Z

move-result v0

if-eqz v0, :cond_6

.line 875
iget-object v0, p0, Lcom/android/settings/DisplaySettings;->mDisplayBatteryLevel:Landroid/preference/CheckBoxPreference;

invoke-virtual {v0}, Landroid/preference/CheckBoxPreference;->isChecked()Z

move-result v0

.line 876
invoke-virtual {p0}, Lcom/android/settings/DisplaySettings;->getContentResolver()Landroid/content/ContentResolver;

move-result-object v3

const-string v4, "display_battery_percentage"

if-eqz v0, :cond_5

move v2, v1

:cond_5
invoke-static {v3, v4, v2}, Landroid/provider/Settings$System;->putInt(Landroid/content/ContentResolver;Ljava/lang/String;I)Z

goto :goto_2

.line 878
:cond_6
[COLOR="red"]iget-object v0, p0, Lcom/android/settings/DisplaySettings;->mBrightnessSliderPreference:Landroid/preference/CheckBoxPreference;

invoke-virtual {p2, v0}, Ljava/lang/Object;->equals(Ljava/lang/Object;)Z

move-result v0

if-eqz v0, :cond_next

iget-object v0, p0, Lcom/android/settings/DisplaySettings;->mBrightnessSliderPreference:Landroid/preference/CheckBoxPreference;

invoke-virtual {v0}, Landroid/preference/CheckBoxPreference;->isChecked()Z

move-result v0

invoke-virtual {p0}, Lcom/android/settings/DisplaySettings;->getContentResolver()Landroid/content/ContentResolver;

move-result-object v3

const-string v4, "display_brightness_slider"

if-eqz v0, :cond_bright

move v2, v1

:cond_bright
invoke-static {v3, v4, v2}, Landroid/provider/Settings$System;->putInt(Landroid/content/ContentResolver;Ljava/lang/String;I)Z

goto :goto_2

:cond_next[/COLOR]
iget-object v0, p0, Lcom/android/settings/DisplaySettings;->mNotificationPulse:Landroid/preference/CheckBoxPreference;

if-ne p2, v0, :cond_8

.line 879
iget-object v0, p0, Lcom/android/settings/DisplaySettings;->mNotificationPulse:Landroid/preference/CheckBoxPreference;

invoke-virtual {v0}, Landroid/preference/CheckBoxPreference;->isChecked()Z

move-result v0

That's it for SecSettings. Recompile and move on to SystemUI.