To see an expedited demo, watch the video up top.
If you’re concerned about relying solely on light to wake you up, you can set a sound as well. Five different sounds are built in, including a standard beeping noise to more soothing options like the ocean. You can’t wake up to your own music (or whatever else you might choose), but hopefully we’ll see that feature added in the future. For now, Wake Up Light is still a solid alternative to much pricier hardware that can do the same thing.
Wake Up Light ($4.49) [Mac App Store]