How to add custom anchorns to buttons

Hi!

I need to make interface that will work in different resolutions.

I set anchors of buttons on stretch mode and after changing of resolution there is nothing on the screen. After it i set anchors of one button on custom mode and placed anchors on the corners of the button. Result is perfect, but it is necessarily to make all manually. It's not precision and takes lot of time. Besides I have above 50 elements in one screen and it is real horror to change positions or sizes of elements after setted anchors. How to make adaptive interface right?

Thank you