Constantly crashes under iOS 13 – Marvin 3 Review

I've had this program for a couple years and it worked perfectly, holding a library of several thousand books. With the iOS update, it started crashing nonstop. I can get it to work with a couple dozen books in the library, but it crashes and then won't work. Once it crashes, there's no way to make it operate. I have to delete it, re-download the program (which deletes all the books), and work again until it inevitably crashes, rendering it useless. It hasn't been updated for some time. It's the best ePub reader I've used; sorry to have to retire it unless a more recent update shows up. I'd even happily pay for Marvin 4, if it works with iOS 13.
Review by nozakit on Marvin 3.