Here’s an open source component allowing you to create highly customizable buttons in iOS 8 with a nice vibrancy effect (and within iOS 7 without vibrancy) called AYVibrantButton from Alan Yip.

AYVibrantButton supports too different styles (invert and translucent), and allows you to customize the background color, text, font, and border width and corner radius. You can set the UIVibrancyEffect as desired with the default being a blurring effect.

Here’s an image from the readme showing the invert style with vibrancy effect:

You can find AYVibrantButton on Github here.