It would be simple to make almost everything configurable with a text file that specifies some default themes for users to choose. More advanced users could edit the numbers (colors, positions, sizes) directly. Maybe this would be good for a possible new version? Graphics can also be changed, actually that already works. They're stored as PNG files in the tablet.

The actual code is very short and easy to modify for any home applet. Sadly I can't publish it but I'm planning to make some unrelated homescreen applet from scratch as open source.

As for free weather information we have some but you'd have to ask sales, see "contact" in corporate.foreca.com. They're friendly and happy to help.