The code is released under the GNU General Public License.
In order to built this project you need to download Android Studio.
This app is to be meant to be used with the drone draw demo located at the following repository: https://github.com/HovakimyanResearch/crazyflie-demos.
More information can be found at the following blog post: http://blog.tkjelectronics.dk/2016/12/painting-with-drones.
For more information send me an email at lauszus@gmail.com.