How can I use Appstore API to get top100 list? What is the common architecture to build a appstore application website?

Question

1. I've found a PDF file of Appstore search API, that I can use some parameters to fetch an application's detail information.(sorry I forgot the download url, but I found it in stackoverflow)
   But there are so many sites that show you a Top100 list(like appshopper.com), and such as Mobclix.com also provide you the rank information.How can they do that? I didn't find the related API in the PDF file.
   I also found an Appstore API by ABTO(http://www.abtollc.com/AppStoreAPI.aspx), but I really wanna do it by myself.

2. If I clear the 1st question, then I'd like to know the common architecture of building a website based on the appstore data. Do I need a database to cache the appstore's data, and create a batch to fetch the data frequently, execute like once per hour? I think it might not be clever to access the appstore for every user request, and may be there is a access limit of appstore?

Thanks for your help!

Answer 1

1.The way people do to get information from the AppStore is to parse the Xml returned from ITunes web call, and get the information they want. There's no official api release from apple.

1. You may be right, its more clever to save a copy of app information on your server.

Answer 2

You can use the following link to generate a url for querying iTunes Data for things like the top 100 apps in a particular category.

http://itunes.apple.com/rss/generator/

For the top 100 free productivity apps the generated url is

http://ax.itunes.apple.com/WebObjects/MZStoreServices.woa/ws/RSS/topfreeapplications/sf=143441/limit=100/genre=6007/xml

The PDF that you link to is very old and hasn't been updated in quite some time, but even if you did get that working, it doesn't have "Top 100" selections (to my knowledge).