[One (M7) Android Development] andybones:
I have seen a few people wondering how this is done, and I haven't found any tutorials on it so I figured I'd do my best to create one as detailed and straight-forward as possible.

Although Android 4.4.2 is a bit old I still figured it's worth mentioned in here how to do it for that platform of Android.

For Android 4.4.2 they made it a bit more difficult than what we see in Android 4.4.3 and Android 4.4.4, and for this you will need to know how to use apktool or your favorite editing tool to decompile the ExtremePowerSaver.apk.

Once within that application the methods for changing the applications are the same it's just a matter of different locations for Android 4.4.2 and 4.4.3/4.4.4. Once you have the application decompiled, then it is into \res\xml\default_workspace.xml.

Within this XML you will find the package name of the applications. To change an app you will need to get the package name and class usually from the Android-Manifest from the application you want to change to.

Now onto Android 4.4.3:

This location is much easier and doesn't require any decompiling. Instead we are going to go into the ROMs system\customize\MNS\default.xml.

Once within this XML you can do a search for "<module name="PowerSavingLauncher">"

The stock set-up looks like this:

<module name="PowerSavingLauncher">
<function name="1_shortcuts">
<set name="plenty">
<!--d4bfa4f3-19e4-4792-97bf-89c39e887971-->
<item name="package">com.htc.contacts</item>
<item name="class">com.htc.contacts.DialerTabActivity</item>
<item name="screen">0</item>
<item name="x">0</item>
<item name="y">0</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--95397c50-60a0-40ec-aba0-8ce6e86570d2-->
<item name="package">com.htc.sense.mms</item>
<item name="class">com.htc.sense.mms.ui.MessageTabActivity</item>
<item name="screen">0</item>
<item name="x">1</item>
<item name="y">0</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--2cb246a4-4c84-461f-a70f-9b17f4798dfd-->
<item name="package">[COLOR="Red"]com.htc.android.mail[/COLOR]</item>
<item name="class">[COLOR="Red"]com.htc.android.mail.MultipleActivitiesMain[/COLOR]</item>
<item name="screen">0</item>
<item name="x">0</item>
<item name="y">1</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--cdb79c92-5755-4d18-870d-a3fa748229cc-->
<item name="package">[COLOR="Red"]com.htc.calendar[/COLOR]</item>
<item name="class">[COLOR="Red"]com.htc.calendar.CalendarActivityMain[/COLOR]</item>
<item name="screen">0</item>
<item name="x">1</item>
<item name="y">1</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--ada42e3e-eb4d-4bd4-a6d8-92cbf3c446d9-->
<item name="package">[COLOR="Red"]com.htc.sense.mms[/COLOR]</item>
<item name="class">[COLOR="Red"]com.htc.sense.mms.ui.CmasListActivityShortCut[/COLOR]</item>
<item name="screen">0</item>
<item name="x">0</item>
<item name="y">2</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--d15a3eca-ea10-443f-baa2-67399af92748-->
<item name="package">com.htc.powersavinglauncher</item>
<item name="class">com.htc.powersavinglauncher.Launcher$Exit</item>
<item name="screen">0</item>
<item name="x">1</item>
<item name="y">2</item>
<item name="itemtype">0</item>
</set>
</function>
</module>

I highlighted the code that I changed.

You will need to find the class and package name for your application.

(This same method applies to the ExtremePowerSaver.apk, once in that app you will find the exact same code and edit it the same way, but as mentioned above this is usually for 4.4.2.. IF you edit the MNS/default.xml and it doesn't change the application then you MAY need to edit that .apk - I personally have only needed to edit the system/customize/MNS/default.xml for both Android 4.4.3 and Android 4.4.4 KitKat.

This is what I have changed mine to in my BoneStockROM: Mail to GMail, Calendar to Camera, and Alerts to Hangouts.

You may change whatever apps you want.

<module name="PowerSavingLauncher">
<function name="1_shortcuts">
<set name="plenty">
<!--dbacf1b4-3b89-4e8b-bb98-b2e828aa56c6-->
<item name="package">com.htc.contacts</item>
<item name="class">com.htc.contacts.DialerTabActivity</item>
<item name="screen">0</item>
<item name="x">0</item>
<item name="y">0</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--a59b7781-4695-4abf-9e73-ea796637194a-->
<item name="package">com.htc.sense.mms</item>
<item name="class">com.htc.sense.mms.ui.MessageTabActivity</item>
<item name="screen">0</item>
<item name="x">1</item>
<item name="y">0</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--c5e85742-d69d-4003-a318-a5180143b2e0-->
<item name="package">[COLOR="Red"]com.google.android.gm[/COLOR]</item>
<item name="class">[COLOR="Red"]com.google.android.gm.ConversationListActivityGmail[/COLOR]</item>
<item name="screen">0</item>
<item name="x">0</item>
<item name="y">1</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--ed1558ce-c294-44b1-bd9f-d022c796eb21-->
<item name="package">[COLOR="Red"]com.htc.camera[/COLOR]</item>
<item name="class">[COLOR="Red"]com.htc.camera.CameraEntry[/COLOR]</item>
<item name="screen">0</item>
<item name="x">1</item>
<item name="y">1</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--b7f07b18-090a-40b0-af8b-e39fb0cb441d-->
<item name="package">[COLOR="Red"]com.google.android.talk[/COLOR]</item>
<item name="class">[COLOR="Red"]com.google.android.talk.SigningInActivity[/COLOR]</item>
<item name="screen">0</item>
<item name="x">0</item>
<item name="y">2</item>
<item name="itemtype">0</item>
</set>
<set name="plenty">
<!--fe3adb77-f8a3-4fb3-a8b7-7518a30e7f13-->
<item name="package">com.htc.powersavinglauncher</item>
<item name="class">com.htc.powersavinglauncher.Launcher$Exit</item>
<item name="screen">0</item>
<item name="x">1</item>
<item name="y">2</item>
<item name="itemtype">0</item>
</set>
</function>
</module>

Hopefully this helps those out, please feel free to post questions in this thread and I will do my best to answer them for you.