For my iphone 6 , when i add 4 squares next to reach other , there are some gaps between some squares altough there mustn't. I use for left : 0%x , 25%x,50%x ,75%x . After some tests JanPRO found out the following :
The result of operations like 25%X are often decimal digits, for the iPhone 6s for example: 25%X = 103.5, but the designer converts this value to103.
So when you check the left property of for example button in the code, the value is 103, but this is wrong, it must be 103.5.
sorry . I put the wrong bil file. here it is is. there are no 4 squares. There are buttons like the calculators between the buttons 2 , 5 , 8 and 3, 6 , 9 there is small gap in iphone6