A Dual Band Router will work for a 2.4Ghz device without conflict.

Just Google on wifi controlled outdoor time switch

But A Modest Example

The point of a dual band router/access point is not not that any particular device uses both at the same time, but that the access point will support devices on either band. Hence, a 2.4g device should work just fine.

The problem is that some of these doo-dads aren't really wifi but some other short range wireless protocol (ZibBee, ZWave, sometimes even Bluetooth) and need a hub.

Even those that can speak wifi directly, will require some sort of hub or other local device to make them available to the "cloud" (and hence a non-local phone) as your internet router almost certainly firewalls off your local network (via NAT and the like), but some devices will talk directly to some outside server.

Try this one: http://www.eco-plugs.net/en/products/class.php?classid=8