Taking this picture and problem space into account John Hazen (the author of this Building Windows 8 blog posting) further explains what Microsoft means by application confidence with the following quote;
"Picture a customer browsing the Windows Store looking at a Metro style app; we want them to be thinking only about the app and whether or not it is right for them. We want them to assume—in fact be confident—that the app will behave the way they expect and thus will perform well on their system, will use only the data and information they authorize, and will harmoniously co-exist with their other applications."
Microsoft's App Confidence for Metro Apps in Windows 8 appears to be built on the following foundations;
- App Capability Declarations: Does the data Metro App need access to local data/device/network/user functionality
- Data Libraries: This means private/separate data in application specific locations
- Network Access: allows for the lock-down or access to the network/Internet
- User Identity: allows for authentication and identification
This looks like a great platform for Metro App development, as I love the idea of a "frictionless install" and separate/private areas for application settings and data.
If you are interested in how developing for Windows 8 Metro Apps compares with Apple iOS applications, please read here: http://msdn.microsoft.com/en-us/library/windows/apps/hh868262.aspx
Delivering reliable and trustworthy Metro style Apps