I was way too long silent. Too much work at work and I did one other app, for which I will write soon.

As of few weeks ago the Android and the iPhone versions are free.

You can get them from here:

Android: https://play.google.com/store/apps/details?id=com.fos4o.defoflight

iPhone: https://itunes.apple.com/us/app/defender-of-light/id623430657?ls=1&mt=8