I'm experiencing the same problem. My Lightroom app wouldn't open anymore just automatically closed when I tried. So I ended up having to delete the app and download it again. Which I thought would be fine considering I had a login attached to my email. They're all gone! My paid presets and treasured photos. I'm devastated! Help. Can I get these back somehow?!
Split from thread since the other case is a different one.
@Kristin I'm sorry to hear that you've run into this issue. It seems like you are using a free account which doesn't sync, in that case any uninstall will cause all data in the app to be wiped.
If possible, always backup your phone, that should save yourself from losing too much data in case of an issue like the one you mentioned. In the case of a recurring startup crasher, please always post in the forum for us to be able to investigate and fix the issue. Helpful information is device type and iOS version.