Added CSS3 timing functions

app/assets/stylesheets/_bourbon.scss

@@ -18,6 +18,7 @@
 @import "css3/transition";
 
 // Addons & other mixins
+@import "addons/animation-keyframes";
 @import "addons/button";
 @import "addons/position";
-@import "addons/animation-keyframes";
+@import "addons/timing-functions";

app/assets/stylesheets/addons/_timing-functions.scss

@@ -0,0 +1,29 @@
+// CSS cubic-bezier timing functions. Timing functions courtesy of jquery.easie (github.com/jaukia/easie)
+// Timing functions are the same as demo'ed here: http://jqueryui.com/demos/effect/easing.html
+
+// EASE IN
+$ease-in-quad:      cubic-bezier(0.550, 0.085, 0.680, 0.530);
+$ease-in-cubic:     cubic-bezier(0.550, 0.055, 0.675, 0.190);
+$ease-in-quart:     cubic-bezier(1.895, 0.030, 0.685, 0.220);
+$ease-in-quint:     cubic-bezier(0.755, 0.050, 0.855, 0.060);
+$ease-in-sine:      cubic-bezier(0.470, 0.000, 0.745, 0.715);
+$ease-in-expo:      cubic-bezier(0.950, 0.050, 0.795, 0.035);
+$ease-in-circ:      cubic-bezier(0.600, 0.040, 0.980, 0.335);
+
+// EASE OUT
+$ease-out-quad:     cubic-bezier(0.250, 0.460, 0.450, 0.940);
+$ease-out-cubic:    cubic-bezier(0.215, 0.610, 0.355, 1.000);
+$ease-out-quart:    cubic-bezier(0.165, 0.840, 0.440, 1.000);
+$ease-out-quint:    cubic-bezier(0.230, 1.000, 0.320, 1.000);
+$ease-out-sine:     cubic-bezier(0.390, 0.575, 0.565, 1.000);
+$ease-out-expo:     cubic-bezier(0.190, 1.000, 0.220, 1.000);
+$ease-out-circ:     cubic-bezier(0.075, 0.820, 0.165, 1.000);
+
+// EASE IN OUT
+$ease-in-out-quad:  cubic-bezier(0.455, 0.030, 0.515, 0.955);
+$ease-in-out-cubic: cubic-bezier(0.645, 0.045, 0.355, 1.000);
+$ease-in-out-quart: cubic-bezier(0.770, 0.000, 0.175, 1.000);
+$ease-in-out-quint: cubic-bezier(0.860, 0.000, 0.070, 1.000);
+$ease-in-out-sine:  cubic-bezier(0.445, 0.050, 0.550, 0.950);
+$ease-in-out-expo:  cubic-bezier(1.000, 0.000, 0.000, 1.000);
+$ease-in-out-circ:  cubic-bezier(0.785, 0.135, 0.150, 0.860);

readme.md

@@ -309,6 +309,16 @@ Create beautiful buttons by defining a style and color argument; using a single
     }
 
 
+###Timing functions
+These CSS cubic-bezier timing functions are variables that can be used with CSS3 animations. The provided timing functions are the same as the jQuery UI demo: [easing functions](http://jqueryui.com/demos/effect/easing.html).  
+
+    Variables supported: $ease-in-*, $ease-out-*, $ease-in-out-*
+    * = [quad, cubic, quart, quint, sine, expo, circ]
+
+    @include animation-timing-function($ease-in-circ);
+    @include animation-basic(fade-in, 1s, $ease-in-quad);
+
+
 #All Supported Functions, Mixins, and Addons
 *@ denotes a mixin and must be prefaced with @include*
 
@@ -370,6 +380,7 @@ Create beautiful buttons by defining a style and color argument; using a single
       animation-keyframes (fade-in, fade-out)
     @ button(*args)
     @ position(*args)
+      timing-functions (fade-in-*, fade-out-*, fade-in-out-*)
 
 
 ##Help Out