There's a great port of this on Android: https://play.google.com/store/apps/details?id=com.androthsof...
And I couldn't even access the developer's website (www.androthsoft.com). If the money went to the authors/official website I'd buy it in a heartbeat, but in the current situation I'd rather circumvent the official download channels...
https://github.com/cjhopman/Wesnoth-1.8-for-Android
The "Is that legal?" question is extremely complicated because you're looking for a positive answer in a marketplace full of a bazillion theoretical negative answers. They're not "selling GPL without releasing the source" as long as github doesn't go out of business. Is it legal, in the sense that there used to be a raging debate if your agreement to sell on the apple store was invalid thus illegal if you "sold" GPL'd software, which I stopped caring about once I got rid of my last iDevice and went all Android, so it may or may not be legal to "sell" GPL software on at least some app stores. Another app store example, for no reason I'm aware of, wesnoth used to be stuck in the incoming queue on fdroid, I donno why or if that was ever resolved or if it had anything to do at all with the license.
"If the money went to the authors/official website I'd buy it in a heartbeat"
Well, CJ is listed by name on
http://wiki.wesnoth.org/Credits
Along with about 500 other people. I suppose paying one of the 500 is superior to paying none of them. Personally I think the work he did to port is worth a "tip" so I paid for it a long time ago.