LightSpeed (http://www.lightspeedretail.com/) reinvents the in-store shopping experience for today's iGeneration shoppers with a robust, fully-integrated retail system that turns Macs, iPads, andiPhones into cutting edge point of sale and retail management tools. It is multi-user,multi-store, eCommerce-ready and extensible through a developer API so that software never limits retail aspirations.
The integration is easy, just edit file templates/_yourtheme/orderview.tpl.php and insert the following code just below the line with text if($this->order):_
That's it, save your work and you are good to go.
Do not forget to integrate your site with the click tracking code. You can do that by inserting the click tracking code to global footer file in templates.