There are a few good packages out there that usually use the iphone/iPad app, an artnet - dmx node, and a wireless router.
The problem with any system like this is reliability and redundancy. If any part of the chain fails or develops gremlins you are in trouble.
Purpose built consoles like those from ETC, MA Lighting, and in recent times Chamsys are built specifically to control lighting, and are incredibly stable, especially when mainly driving conventional lamps.
On bigger productions the iPad or iphone is used as a remote control unit for a large console like a GrandMA or similar. All the processing is still done by the console, the majority of the programming, patching, etc, is still done on the console, with the iphone used to trim levels on set with the gaffer and DP, and hit the go button on cues. The big advantage to this is if the wireless fails, the board operator can just head back to the console all data intact, having never lost control of the system.
Also, despite how stable the consoles are, more often than not you will have a redundant console, whether in the form of a second full console, or a laptop running as a slave so the ability to control the lighting system is maintained at all times even if the master console crashes or fails.
I have used a laptop based system with an iphone as a remote before for a couple smaller sets very successfully, but never had complete faith in the system.
LEDs make things a little more difficult again. Unlike conventionals where you can patch them into a feed that is patched through a specific dimmer channel, LED heads need to have DMX cable run to them directly, which with the way dmx works by daisy chaining fixtures can really slow things down once you start bouncing lamps around a set.
Its a cool concept, but rather than making things more simple, on a small scale job, where you aren't using a complex lighting control network already, it can complicate things and add multiple extra points of failure.
Edited by Matthew Parnell, 11 February 2014 - 09:11 AM.