Golf Pad displays GPS rangefinder distances to the front, middle and back of the green, right in the phone notification area. So you can easily check the distances without unlocking the phone. This features is available on Android phones.
How to access rangefinder distances without unlocking the phone
Start a new round as you usually do and enter scores. Hold down the notification area by pulling the status bar and you'll see the data for the current hole. It includes distances to the front, middle and back of the green, hole number, par, score and course name. You can switch holes by tapping right and left arrows and easily open the Golf Pad app by tapping the distance in the notification.
See how it looks like: