With Close Threshold for Windows 8.1 you will able:
- to speed up Metro apps closing with mouse
- to speed up Metro apps closing with touch gestures
- to speed up the "flip to close" feature.
Close Threshold for Windows 8.1 works only with Windows 8.1 RTM. Freeware & Portable.
If you are curious how does it work, here is the detailed guide for you: How to reduce distance to drag close Metro apps and speed up closing in Windows 8.1