RMTextViewPlaceholder is a subclass of UITextView. It adds support for placeholder text, which is not available by default (only UILabel has placeholder). The class is written Swift and makes use of the new @IBDesignable and @IBInspectable functionalities.
Thus, you can set a UITextView in Interface Builder to use RMTextViewPlaceholder and direclty define the placeholder text, the placeholder text color and the placeholder background color.
Under the hood, RMTextViewPlaceholder just adds a UILabel acting as a placeholder and observes the UITextViewTextDidChangeNotification.
RMTextViewPlaceholder.swift needs to be located in a framework to be rendered in Interface Builder. Also, make sure that the class is targeted for your main project otherwise you won't be able to use it in your code!
Have Fun!