Zen Wave will help you get to sleep when your head is full of thoughts. It will display a gently ebbing and flowing light. You can inhale an exhale in sync with the light which will gradually slow down and help you relax until you have reached sleep.
You should put the device beside your bed, with the display facing to the ceiling.
If you want to, Zen Wave will also wake you up with during a 14 min period with a sound you choose the gradually increases in volume and tempo. Your day will begin in grace and beauty.
The function of this app is similar to the device described by Timothy Ferris in THe 4-Hour Body.
Usage
To add your own personal Zen Wave for sleeping and waking up, go to My Waves, click Edit and then Add Zen Wave. You can then choose the duration, your start breathing rate and your sleep breathing rate, the color of the pulsing light, the alarm time and sound.
If the light is to weak, go to Settings → Brightness, turn off Auto-Brightness and move the brightness slider all the way to the right.
Disclaimer
If you suffer from serious onset insomnia this app might help you, but if not you should seek out the help of a professional. Do not use with children below one year of age. When using this app, it is best to turn on your devices airplane mode to avoid unnecessary exposure to radio waves during sleep, as these might be a reason for insomnia.