Just released is an excellent remote controller for using with an iPad, IPhone and worth a look as it is not just an image transfer download remote controller but also a remote camera controller all done wirelessly. Nearly all camera setting including focus can be controlled from a distance of up to a minimum distance of 150 metres. At this time there are a limited number of cameras being compatible with it with a promise of many more to come.
I have no business interest with this company other than being very excited about this product as it is something I've waited for for a very long time.
www.camranger.com
John
Happy Christmas