Quick Launch lets you jump from a watchface to your favorite Pebble apps, delivering the information you want and allowing you to take action quickly and cleanly.
On PebbleOS all four buttons can be assigned for Quick Launch.
Please note: the Quiet Time feature is assigned to the Back button by default, but can be reassigned.
To use Quick Launch, simply press and hold the assigned button for 2 seconds. The app that you have assigned to that button will immediately launch for use.
Configuring Quick Launch
Select Settings from the main menu on your Pebble
Select Quick Launch
Press Select when the button you want to assign is highlighted
Choose from the list of available apps
You're done!