Nothing is for free? Well, this is as close as I can get.
No adverts. No tracking of your data. No in-game payments. No subscribing to a mailing list.
Donations (of whatever amount you choose) would be very much appreciated, but only if: You like the game or want to show your appreciation or want to support further development (Android version?) or if you just want to help out :-)
Please don't send anything if you can't really afford to!
If you need to contact the developer, please e-mail me.