Only the current version so far — new entries appear as the app ships updates.
Sleepy Sounds is a lifestyle app by OwenTech with 1,000,000+ downloads (about 1.2M estimated). Rated 4.3 from 8.9K ratings. Released Jun 8, 2011. Install growth, rank history, SDKs and ad networks.
From the store listing: “Sleepy Sounds helps you or your child fall asleep”