Round Corners

In Illustrator CS5, is there a (free) script that can replicate live corners in Adobe Illustrator CC?

When designing graphics in Illustrator CS5, how can I make a shape (i.e. circle) snap to a curve at any point (instead of limited to just the anchor points) and any angle (instead of just right angles). Smart guides don't seem to be enough. Can this be achieved by adjusting the smart guides preferences? Is there a script that will allow shapes to snap at any point nearby -- similar to the dolphin illustration below?

Thanks in advance!