UPDATE This crash seems to have stopped occurring since iOS 7.1 was release. At this time (4th April) I haven't seen any occurrences on iOS 7.1 when I was seeing it more about weekly on iOS 7.0x. Several other crash types have also not been observed on iOS 7.1 although two instances of a different crash have been seen.
Most software crashes sometimes and unfortunately this includes Fast Lists. At the moment I have records of 12 crashes in the latest version (2.04) that was released about a month ago (18th Feb). On many occasions crashes are clearly caused within the software I have developed whether due to my mistake or the libraries (both Apple and 3rd party) that I use having bugs and not and not behaving as documented. This post is about several crash reports that appear to be occurring deep within Apple's code (although quite possibly due to my own incorrect software), it includes the crash reports very slightly redacted and what I have currently deduced about the cause.
I think the general interest in this post for non-developers will be pretty close to zero.