App won’t open

I hav an app that’s no longer on the AppStore called PlayerIL. It’s a music app, it’s been working fine until today when it crashed on me and won’t let me open it again. I’ve cleared it from the recent apps and tried to reopen did nothing, I’ve restarted my phone did nothing, and I’ve force restarted my phone still did nothing. I would offload the app but because it’s no longer on the AppStore I don’t want to lose all my data and not be able to redownload it again. I don’t know what else to do to get the app open please help.