You should definitely be releasing both btMonitoredDevicesbtMonitoredDevices and btPairedDevicesbtPairedDevices in the deallocdealloc. But it appears that this is your appDelegate so it matters little outside of correctness. I'd do it anyhow.
You shouldn't need the retainretain on btMonitoredDevicesbtMonitoredDevices since you're calling allocalloc on it. So you already have a retainretain count of one on it. By calling retainretain on it you actually have a retainretain count of two.
So to sum up make sure you're releasing both in your deallocdealloc and get rid of the [btMonitedDecices retain];[btMonitedDecices retain]; and you should be good.