Digital BW, The Print

The Promote Control has released beta firmware for focus stacking on Canon.

https://support.promotesystems.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=17 

I have one and it works great for HDR, time lapse, and, now, focus stacking.

There is also an Android app for DSLR control https://market.android.com/details?id=eu.chainfire.dslrcontroller 

While this does not have the functions of the Promote Control, one could expect that it could be added in the future.

John