1. We only download apps that specifically do not exclude the US app store. Therefore, if your app does not want traffic in the US (e.g. French-only on demand car service) they may choose to exclude US traffic and this would be why we wouldn’t have them. 
  2. Downloading paid apps would be extremely costly to us, so we do not cover paid apps. 
  3. Some apps obfuscate their code to try to avoid any potentially malicious attacks or to ensure no one tries to copy their app. These apps tend to have highly confidential data, which they wish to secure (e.g. banking). Obfuscation is not easy to do, so this will only be for a small subset of apps that invest heavily in hiding their raw files.