This page is not complete.
There are a number of helpful tools located in the gaia/tools/ directory. This article looks at each one.
This is an image compressor. You can run it with the following command structure:
$ ./tools/png_recompress.sh -v bg.png
This will remove unnecessary metadata and further compress the png; it can save up to 99.5% of the file size, which has a very measurable impact on an app's ZIP size and memory footprint.