apps broken after ios7 update

I released a few apps onto itunes over a year ago. All was great, they run happily on ipads, ipods, various iphones etc. 

I recently updated my ipad2 and ipad2 mini to ios7 and found none of my apps (already installed) now work.

They worked fine until after the update. 

Some dont launch. Some work but only show a black screen, music etc can be heard in the background. 

Does anyone have any ideas what this could be? 

All apps developed with flashbuilder 4.5 with air 2.6.