You can use custom weather icons by placing 64×64 pixel icons in png format in a zip file that you place at: /sdcard/snowstorm
The zip file with a skin i must be named according to “*-skin.zip”, e.g. twcnew-skin.zip
Each icon should be named w<symbolNumber>_<period>.png.
Valid symbol numbers and periods can be found at Yr.
The periods are, 0 = night, 1 = morning, 2 = day, 3 = evening
E.g w4_1.png would be the morning image for a cloudy day.
You can also place an info text with credits etc in info.txt inside the zip. The text file should be saved in UTF-8 without BOM character in the beginning.
A sample skin can be downloaded from the downloads page.
Note that you also can add a custom background to the zip. The background should be 322 x 100 pixels, but remember that the UI guidelines for Android says that you should have a smaller display area.
You can read more about Android UI guidelines here:
Mail me if you want me to link to a skin that you have created, or if you want me to host it: