How to addSubview to the bottom of view hierarchy
"This method moves the specified view to the beginning of the array of views in the subviews property."
[self.view sendSubviewToBack:yourView];
Just put it there directly instead.
[self.view insertSubview:_map atIndex:0];
Swift 3
Swift 4
view.insertSubview(view, at: 0)
Answer by Robert and rcat24 does work. Alternatively,
You can use "zPosition"
subViewToBeOnTop.layer.zPosition=1.0;
subViewToBeOnBottom.layer.zPosition=.9;
1 being top most, 0 being least.