Five applications that will help you to get to sleep at night and leave you feeling rested and awake in the morning.

Sleep Cycle alarm clock
Sleep Cycle alarm clock is a futuristic alarm clock that monitors your sleeping patterns and wakes you up when your body is naturally in its lightest sleep phase. People who suffer from a lack of sleep or who feel tired and groggy in the mornings swear by it. You'll have to love your iPhone enough to sleep with it but you needn't worry as whilst your phone is in your bed its busy tracking your movements and forming a detailed graph of your whole night's sleep. In the morning the alarm clock judge the optimal time within a user-defined window of 30 minutes at which to wake you.
Price: $0.99

Branded as an "environment enhancer" Ambiance features more than 600 free ambient sounds that are designed to help you enter a state of deep relaxation. The app comes with 3 included sounds after which you can find and download additional tracks (for free) through the application to create your own special collection of relaxing sounds. Sounds can be mixed together with other sounds or songs from your iTunes playlist. To make sounds easier to find you can favorite them, create customized playlists, categorize your sounds into groups, and even share sounds wirelessly between two devices.
Price: $0.99

Alarm Clock Pro
Alarm Clock Pro is an application that enables you to wake up to your favorite music or your personal iTunes playlist. The app also doubles as a flashlight for night-time emergencies. Users can pick from a variety of clock face themes, set multiple alarms for different days and times and customise the "snooze" time after an alarm.
Price: $0.99

Pure Sleep - AmbiScience Sleep Aid
Pure sleep by Tesla Software uses different frequency sound waves and relaxing sound patterns to help you get to sleep. The app features nine different tracks and three different sleep modes.
The ambient sounds found on tracks like "An Android's Dream" or "High Plains Japan" are designed to re-sync your brainwave patterns helping you to close your eyes and enter a deep sleep, a peaceful slumber or a power nap.
Price: $0.99

iRelax Melodies (sleep & meditation & yoga & relaxation) helper
iRelax Melodies is a free application that lets you create your own relaxation music. Users can select from 16 different natural-sounding audio loops such as river, ocean, rain, winds or birds and mix them together to form their own relaxation soundtrack. Compositions can be saved for future play back. The inbuilt timer turns the sounds off after a set period of time if you the app to help you fall asleep at night.
Price: Free