Web application development for retail store chain

For a retail chain store, we need a web application to give to our shoppers. We do not need to do ecommerce in the application and thus do not need to link to our items or catalog. The features that we need are: 1. Simple customer registration via sms. We will just take the name(optional), email (optional) and mobile number and send a welcome sms message to the customer. User can register himself or our staff can register them by adding their details on a web url or via sms only (by sending an sms with name and email to our local number - which should somehow reach your system which will register the user in your database and send user a welcome message). Duplicates should not be allowed of course. As administrators we must be able to remove particular users too from the system. 2. Loyalty program - points based system that identifies the customer and adds points at our checkout counters. Customers will give their mobile number to identify themselves and checkout operator should be able to enter purchase amount/points in the system for that [login to view URL] sms should go out notifying the user about the number of points that have been added to his or her account. 3. Besides the automatic notifications as in above, we should be able to push notifications (offers and more) either to all customers/users or users with a certain number of loyalty points or above. We should be able to send push notification to particular user too. And also be able to push notification to users with recent purchases - after a certain date or within the last "n" days. So we will need a Notification sending interface to do this. 4. Customers/users and non-users should be able to request a list of current promotions by sending an sms to our predefined local number. If this request sms comes from Non users, they should automatically be added to our database of registered users. 5. Any other feature suggested by you - please include feature suggestions in your quote/proposals We should be able to customize all push notification messages. If the user has given an email address while registering then we should send notifications to the email address too. You can use twillio api or any other api for mobile/sms. For the emails you can either use the googleapi or mailchimp. You can also suggest the use of a different api that can take care of mobile as well as emails. We are not fixed in our selection of the api yet and hence your suggestions are welcome. Please let us know the cost for using the api separately so that we know that operational cost too.