Hello folks,
We are currently testing WeatherCat on the GM of Mavericks and have become aware of a potential crash that can occur at random intervals when running on 10.9.
We are working on this, and will have a fix out as soon as possible, but for now suggest you do not upgrade to Mac OS 10.9 if you want to run WeatherCat.
We apologise for any inconvenience this may cause.
Update: It looks like a problem with the Webcam preview window - if this is open, it will crash sooner or later. The work-around for now is to close the webcam preview window when your not using it.