Windows 8 - Lock Screen
★ How to add To-Do Prime app to lock screen?
Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.
(If you're using a mouse, point to the lower-right corner of the screen, move the mouse pointer up, click Settings, and then click Change PC settings.)
Tap or click PC and devices, and then tap or click Lock screen.
Under Lock screen apps, tap or click the plus button . Then tap or click on To-DO Prime app in the list to select it.