I just begin swift and I'm facing a simple problem: I can't adapt a UIButton to an image in my storyboard for all iPhone size. I work with a storyboard with the size of an iPhone 6s Plus because I have one. When I run my test, all it's OK but when I run my test with iPhone 5 simulator, nothing is good. This image shows the button is in the good place on iPhone 6 plus but no to other sizes. I tried so many different constraints but nothing seem to work.
How can I set constraints to position a button at the circle in the background image (as shown in the link), regardless of phone size?