Website Developement/ Software website.

Need a website developed/online software, that a user can login and then use there credentials from another website/service. Once person enter login then the website would start scanning website for certain parameters such as ROI. Once the software is done scanning the products on that site it will send an email or txt message indicating completion of scans. User can choose to get an email of a buy list that matches criteria with location address, qty available and net ROI.