Apple has discovered an esoteric bug that is causing many newer iPhone models, including iPhone XS, iPhone X, and iPhone 8, to repeatedly crash and respring (display a black loading spinner) when the GasBuddy app is installed. The issue was
first publicized by MacRumors. An anonymous Apple retail employee
posted the fix on Reddit earlier. GasBuddy has said it is
working on a fix. Apple retail has been advised to uninstall the app in the meantime. It's not clear exactly what is causing the issue. It is very rare for a single iOS app to be able to overload a system like this. GasBuddy is likely exposing some bug in an Apple system API like background task management.
Neither Apple nor GasBuddy has disclosed a full explanation of what is going on. At the present time, Apple has not even made a public comment on the matter; retail store support employees have been notified of the problem in an internal memo.
If your own iPhone is afflicted by this problem, restart the phone by pressing volume up, volume down and then holding the power button until the device reboots. You can then promptly uninstall GasBuddy when you return to the Home Screen. You can re-download the app later when the fix is distributed. Until the bug is resolved, GasBuddy has temporarily pulled its app from the App Store.
Update: GasBuddy has now been updated that "resolves an issue that was causing some devices to crash".
Get the new version from the App Store.