I've installed an app from the Windows Phones Store called "360手机卫士", a so-called famous(or infamous) antivirus software in china, which is said to be able to check your installed apps. After using it, I found that during the scan process,it does get the list of all my apps and scanned them. So after checking on the internet I get to know usually apps can't get the list because of "sandbox". How did it passed through or how did this app made it?
BTW:the download of this app. Make sure you use WP8.1GDR2 if you are afraid of it peeking your contacts. http://www.windowsphone.com/s?appid=245303df-88cc-44d9-83ae-dc687fea0b28
Getting info about other apps requires some special/restricted capabilities that are only available to apps that are developed by Microsoft and its partners (Qihoo 360 is one of MS's partners). I can't find reference for WP but this is what I find about Windows Store app.
App capability declarations- there is an
Other App Mangement
capability in the restricted list.And