I have used this app during the day when I am tired, for a quick pick-me-up, and at home for a 20 or 60 minute nap. It absolutely works and makes me feel refreshed and ready to go again for hours. Some of the sounds bug me, but I just change it for one that works for me. I find that the timer works great and wakes you up gently but firmly when the time is up. No worries about sleeping too long.
Storm1947 about SleepStream Classic - Advanced Sleep Inducer & Energizer