Windows 8 comes with plenty of free apps, and you'll find plenty more in the Windows Store. Unfortunately, many Windows 8 users have found that these apps have limited functionality compared to the desktop programs they've used for years. Skype users, for instance, have griped about the confusing interface and lack of features of the Modern UI version of the Microsoft-owned VoIP app. And Window 8/RT's Calendar, Mail and People apps have taken their licks for being underpowered and oversimplified. And while that's fine for mobile apps, PC users want more. To be fair, Microsoft recently beefed up the capabilities of these three apps, but their initial shortcomings show the complexity of developing a single UI and set of apps for mobile and desktop users.