As a SharePoint architect or a SharePoint developer, you must have been thinking about the benefits/limitations of SharePoint apps a lot. I want to point out one of them today, which is very important: using custom webservices deployed to SharePoint inside apps. That is impossible and it is designed to be so due to the security architecture in the sharepoint app framework. I have read much about SharePoint apps (books, whitepapers, blog posts) and stumbled over these two contradictive statements: