Cant believe, i didnt see anyone mentioning this before...
Its a really well made Postapocalyptic Rpg, playing in the Russian wasteland with realistic crafting engine and its really atmospheric in general(especially the soundtrack). Can only recommend... Its a bit slow paced, but still gets updates and its free (premium i like 3€ i think)
Minecraft, exiled Kingdoms and this one are my personal top3 android games.
Vampires Fall:Origins is the only other mobile rpg I have found truly worthwhile. Even it becomes a total grind endgame if you want to be competitive in pvp. Or you can spend real world $ to ease the grind. Fun game tho, good quality old school turn based rpg.