The team have tweaked some of the display settings in the app, and also added a new set of 'skins' that control the weather graphics that are overlaid on your pictures - either taken by the app or chosen from an existing image on your phone.
There's also some performance improvements to help share your weather image with your social networks through the built in share options of Windows Phone.
InstaWeatherPro has had a rough time of it since it appeared on Windows Phone in early August, going through a number of updates to both tweak the code, and add functionality. I'm glad to see they are sticking with the process, interacting on their Facebook page, and getting the app working, rather than leaving it as functional but flawed.
You can download InstaWeatherPro from the AAWP App Directory, for 79p/99c. Unfortunately there's no trial version available - hopefully when all the issues are sorted out, that will be the next step.