Kixeye stated that it's not gonna be supported anymore, and moving to BYM:U.
they do reply to support emails, and where did they say this?
Now KIXEYE's working on two Backyard Monsters. One alive, and one dead.
They probably won't, since they moved to iOS, NOT mobile. Personally, I don't consider iOS a mobile platform, it's more like a outdated mobile platform.
You could wait for android/windows phone release. That's all. I doubt they will revive the original BYM.
I don't think they would.
They're also working on War Commander: Rogue Assault for iOS. AGAIN.
EDIT: But they are releasing Vega Conflict for Android soon (But I'm still done with them).