$2. Current version average rating: 5 stars Designed for iPhone
It may seem odd to recommend a noise app for business, but trust me: If you're a light sleeper who travels often, you’ll want this app. I use it to block ambient sounds when I’m trying to fall asleep in a hotel room during a business trip. I also use the app when I’m working to filter out noise from an adjacent office, so I can concentrate. Along with the White Noise sound, I also like Air Conditioner and Airplane Travel. There are plenty of exotic sounds, too, such as Amazon Jungle, Dish Washer, Cars Driving, Tibetan Singing Bowl, and Cat Purring. The Heartbeat sound might help infants fall asleep, but others may find it a bit too Edgar Allan Poe-ish.