Create Site Similar to Awardwallet.com

I am looking to create a site similar to [login to view URL] -- Awardwallet tracks frequent flyer miles from different airline/hotel/other accounts. User enters their username & password for each frequent flyer program, and awardwallet displays the number of miles in each account, as well as the expiration date from the miles. I assume they do this by logging in, then scraping the information from the site. I would like a similar site built, but not for frequent flyer programs (I will share full information once a developer is chosen), but it will basically be the same thing: users will enter usernames and passwords of sites, and this site will display, basically, two pieces of information scraped from the sites. Initially, I would like to give users the option of 10-15 sites (I'll tell you what those are); they can then choose which they'd like tracked. Again, it will behave exactly the same way as Awardwallet. If the project goes well, there will be additional work developing an iPhone and Android app. I'm happy to answer any questions.