I'm using the beta version. iPhone 5. Was working fine this morning. Now, the moment it launches on my iPhone, it dies. I have killed the app and tried launching again. I have powered the phone down and back up. No luck.

Any suggestions?

Apple says all betas expire in 30 days.
Not sure they will tell you an update is available.
You may have to go to the App Store and SEARCH for FxCal.
Please download 5.2.0 from the App Store.
It is the same code as 5.2.0b11 from TestFlight
Sorry, TestFlight is new to me also.
But it saved some of our bacon on the last VIPS change.
AppDude

Same problem! Went to App Store to my purchased apps and re downloaded it. Works fine!

Same problem - you have to search for it since it won't show up for some unknown reason under UPDATES - however once downloaded it worked fine.