New version with: IB_DESIGNABLE and IBInspectable.

A simple XIB extension to make rounded custom buttons, without writing one line of code, using IBInspectable.

IBInspectable properties provide new access to an old feature: user-defined runtime attributes.
Currently accessible from the identity inspector, these attributes have been available since before
Interface Builder was integrated into Xcode.
They provide a powerful mechanism for configuring any key-value coded property of an instance in a NIB, XIB, or storyboard.

Apple doc: https://developer.apple.com/library/ios/recipes/xcode_help-IB_objects_media/Chapters/CreatingaLiveViewofaCustomObject.html

thanks,
A