I'm impressed that you now put landwar under the GNU GPL V3 license
I'm not great at parsing licenses, GNU seems more software oriented (I am a programmer for a day job, so I gravitated to it.)
I think one of the Creative Commons, maybe CCSA would be more appropriate.
especially Attribution Share Alike 4.0, totally. Maybe you should dual license it under CC-BY-SA 4.0 and GPLv3
I'll make sure the app is under GPL, source code is available over on github.
