Create an App for a mainstream website to alert me on sale

I need an application that will allow me to provide me with the following : -List products on a mainstream website -Update inventory, product price and quantity -Allows user to monitor incoming and pending orders in real-time with an order notification -Allows user to view pending and past order detials for invoicing -Allow tracking for shipped product -View inventory and adjust inventory amounts This app should be very simple to create off of a mainstream website. I need it to log in and monitor all transaction via this app.