Use these steps to use/do/support uninstall and clear cache for apps on the HTC One M8 for Windows.
Clear recent apps
From any open window, touch and hold the Back button.
Each open application appears in a carousel of thumbnails.
Swipe left or right to view the open applications.
Swipe down on a application to end task..
When finished, tap the Back button.
From the start screen, touch the screen and slide left.
Scroll down to the application you want to uninstall.
Touch and hold the application.
Review the warning message, then tap yes.