Create a shape to bend. It must be a group or a component. Then select a single horizontal (red axis) line to use as the base for bending. Then select the curve that the shape will bend to match. Wait for it to think, then it will show a grid and preview of where your object is going to transform to. Press the UP Arrow key to toggle the orientation of the bend.
Access the plugin via Plugins > Chris Fullmer Tools > Shape Bender, or there is a Shape Bender toolbar.