Timelapse Dolly controled by Smartphone App

Excited from some Timelapse videos on YouTube, i wanted to make some Timelapses for my own.
Timelapses are working more realistic, if a think near to the camera moves slowly while recording.
My idea is to use my Android-smartphone to take the picture but also to control the movement after calcing the steps and times between the pictures. The Sourcecode für Android and Adruino is included.

The smartphone connects to this machine via bluetooth. in the wagon an arduino nano mit a accu from RC-