Tablet oriented UIs only work if you're solely consuming material. They really don't work for producing it. That's why Windows had to bring back the start menu, and many larger applications still don't use Metro.
Touchscreen UIs are not for creating. They're for taking what you're given, pecking at giant canned buttons in a dumbed-down UI.
A pigeon can peck the colored button to get a food pellet. That's tablet UI.