Designed mainly as a wired remote with almost full control of the camera, but for me it's a fantastic aid for macro & photo stacking. The DSLR Controller for Android Phones
I've been playing with this 'App' on my Galaxy 111 Android phone. The flower is a 6 image stack. I initially set the camera on the tripod and set the focus on the back edge of the far petal the next 5 shots (focus steps) were totally controlled from my phone.
My apologies for the poor photo, but I set this up on my computer desk and just fired away with one flashgun. The DLSR Controller App offers control over ISO, Aperture. Shutter Speed. Program mode + of course focus. Although still in Beta it's very stable and costs just £5.94. At the moment it's only compatable with the later Canons.