Timing's a pain but like folks here said, Mercury retrograde has nothing to do with your app crashing. That's pure coincidence. Apps break all the time and sometimes it just happens to line up with whatever's going on in the sky. I'd be more annoyed at the developers than at the planets.
First thing - go check if there's actually an update waiting in your app store. Sometimes apps push updates that fix bugs but don't auto-install, and if you're running an older version it might conflict with server changes on their end. If there's an update, grab it. If not, try clearing the app cache (go to your phone settings, find the app, hit storage, clear cache). That usually clears out corrupted data without deleting your accounts or preferences. If that doesn't work, uninstall it completely and reinstall fresh from the app store.
If you're still having problems after all that, you could try contacting their support - they might know about a specific issue going on in July 2026. But honestly I'd be more skeptical about using an app that's this unreliable anyway. There are plenty of other options out there if this one keeps acting up.