All non stock apps are crashing
I have this happen from time to time. My issue is usually just about any application, not just "non-stock". 

To fix it I have to reboot in to the recovery and clear the cache. I believe that it has to do with the number of applications that I have installed, ~105 total, and the amount of data they store in the cache. 

Clearing the cache usually fixes it, but only for a short time, unless I remove some applications. I am now down to about 80 and I haven't had the issue in a couple weeks.