One great component does not a great system make.
The Myfox Home Security system supports up to four cameras, but you'll need to add them on your own at $199 each.
The basic package includes the siren (the large round component), a Wi-Fi bridge (the large circular object sitting on top of the siren), a circular key fob, and one IntelliTag door/window sensor.
The smartphone app (available for Android and iOS) maintains a history of system events.
Operating the siren on battery power is convenient, because you can place it almost anywhere. But I'd worry that the batteries would expire while I was away and the siren would fail just as someone broke in.
The app's user interface mimics the physical buttons on the key fob.