Scale a sprite horizontally as well.

Hi!
I want my GUI elements to scale to fit whole screen. They do scale well when i increase screen height, but they do not scale horizontally.
How can I make them scale horizontally, also I have canvas attached to all my elements and canvas is set to world size.

Please refer to the screenshots so maybe You can see what I mean. I am developing for mobile phones, I know it might look ugly on wider screens but It doesnt matter on moblies.