Modify installed apps

I was asked to show how installed apps can be customized to your needs. Specifically, there is a gallery app which allows you to click the images to see them enlarged on a dark background. Jon wanted to use a white background but there was no such option. So this video shows how to change (hack) the code to achieve a white background.

Note that if you install packages, they will be automatically updated. (You can turn this off.) For that reason, to protect you from loosing any changes, installed packages are read-only. You first have to break that connection to the original package to make it writable - thereby also loosing automatic updates.

Certainly, that's a trade-off.