How to change/modify iOS WorxApp Icons

I was asked how to modify the WorxApp Icons to match the Cooperate Identity Policy. To accomplish this you will need a Mac with XCode installed, an Image Editor like Gimp and of course the .ipa file you want to modify.

Let´s start with extracting the icons from the .ipa file. If you do this by simply extracting the images from the .ipa file you will get the following error in Gimp and similar Programs.


This is absolutely normal since these Images have been optimized. To undo this we need to “uncrush” them. I found a nice script by Peter Boctor which “uncrushes” whole .ipa files. The script can be found here.

Start the script with the .ipa file you want to edit.


After the script successful ended you will find a new folder named like the .ipa file and an Images at the end.

For a better overview I move the files i need to edit to a separate folder. Now you can now start to edit/replace the images as you wish.


After we have finished editing or replacing the images we want to “crush” them again. Since I ‘am a lazy guy I created a little script which “crushes” a whole directory.


for png in `find $1 -name "*.png"`;


echo "crushing $png"

pngcrush -rem allb -brute "$png" temp.png

mv -f temp.png $png


I also added the path to pngcrush binary to my Environment Variable



You´ll start the script with the following command: ./ foldername


Your folder (in my example it´s called “png”) now contains “crushed” .png files which need to be moved to your original .ipa file. To do this I extracted the WorxMail Application folder from the .ipa/Payload folder. After that I opened the WorxMail Package by clicking “Show Package Contents”. Copy the modified Icons from your folder to the WorxMail Package and make sure you replace the files.

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Of course you need to put the WorxMail Application back to the .ipa file. In my case I used WinZip and simply dragged the file to the correct place.


Now it´s time to wrap the app as usual with the MDX Toolkit and upload it to your AppController. If all worked well you can now install/update the customized app which hopefully looks better than mine J


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