This is simply android and arduino program to turn your phone into 3d printer.
Android app have been created white MIT App Inventor.
Phone use png format do display. You can slice your thing by this slicer: http://lautr3k.github.io/SLAcer.js/#
You have to give specific directory on your phone. Begin it whit file:///your_path/ < have to be ended by /
Movie on how it work:
Hardwer connection contain how to connect A4988 steper motor controler and BT HC-06 adapter. Theoretically it should work :) Didnt check whit steper motor connected - waiting for parts to do that