bulk sms sending app - to send free sms to cell phones

we need an app with the following features: - send free bulk sms messages to cell phones -easy access for consumers to easily add their cell phone number to opt in to receive messages -support many users - provide message delivery reports to users - easy removal option for sms recipient - easy cell phone list upload - easy account creation for back office - easy reporting for back office of all user activities -easy account creation for back office manager -needs to be a php based script - coupon enable app. if you are familiar with such an application and how to send free sms to cell phones please reply and submit your bid, thanks, when the right bid arrives ready to start this project immediately.