I’m building an app that contributes to a crowdsourced earthquake early warning network: the device reports anomalous accelerometer readings, a server correlates them across nearby devices, and users farther from the epicenter get a warning seconds ahead. Detection has to continue while the app isn’t in the foreground. I’ve ruled out the obvious paths — CMMotionManager stops on suspension, CMPedometer and CMMotionActivityManager only return historical data, BGTaskScheduler is too infrequent, and CMSensorRecorder is watchOS-only. I’ve also read thread 765258, where DTS confirmed there’s no background capability for accelerometer data and that repurposing another one risks rejection under 2.5.4, so I’m not looking for a workaround. Is there any supported way to do this on iOS, for instance restricted to when the device is stationary and charging? Or is this outside what the platform currently allows? Thanks.