App Detection app for iphone ios 7

I am looking to develop an app which is similar to the app below: [login to view URL] The app needs to detect apps already installed on a users iphone and once these apps have been discovered recommend apps based on these existing apps. I need someone who has experience of developing an app which can detect installed apps. I have researched app discovery and am aware of what is needed but need a developer who can describe exactly how they will detect these apps. This app will also have Facebook and Twitter logins enabled as well as being able to tweet/post from the app. It will also have in-app purchases enabled. The app itself will need to be programmed in native language and is for ios 7 similar in design to IFTTT as below: (Plain simple design which I have designed). [login to view URL] If you are a developer who has experience in app detection and can provide examples of this, then I would be interested to hear from you. I can provide a more detailed spec once I am satisfied that you understand and can develop the app detection part of this app.