THIS THREAD IS NOT MADE FOR THE REASON OF ADVERTISING, IT IS MADE TO HELP PEOPLE RECORD THEIR DREAM CYCLES!

In the app store, there is this free app that records your sleep cycles. Knowing your sleep cycles and waking you up in a REM ( with which this app can help ) can be usefull in order to enter a LD. Search in the app store for 'sleep cycle alarm clock'. There will be a free app ( second in the list ) with a name familiar to the search term. That's the one to choose. Good luck