Just a quick note to say that I had exactly the same issue as BigChiefS4 when I opened Cachly today. The app would constantly crash within a few seconds of starting up. I too could find no crash logs on my iPhone 7 (Cachly 5.0.2 (4)), but I deleted the app and reinstalled it and now it seems to be working okay. I didn't have to log in to Cachly or Geocaching.com after the restart, it already had the user account set up, although I did lose the offline lists I had, but that wasn't a major problem.
Kevin