A while ago, I made a search app using Google Custom Search: <a href="https://itunes.apple.com/app/in-app-search/id908073064" rel="nofollow">https://itunes.apple.com/app/in-app-search/id908073064</a><p>The URX App Search API certainly looks a lot more promising than Google for this purpose. It's good to see the documentation is public now and I'm sure it won't be long before a large number of apps are using this API.<p>One question about the app index: It doesn't specify the availability of apps in different operating systems. I have come across a number of apps whose sites have deep link information only for Android or iOS.<p>Also, it's interesting that IMDb isn't in the list, considering it is one of the most widely cited examples of app deep linking and its complete site index is easily downloaded and you can follow the links to it via /robots.txt.