White noise generators have their places. They commonly get used as sleep machines, or sometimes in offices to cover conversation or other environmental noise. There have been iOS apps that have generated white noise in the past, but not like this.
Why? It’s got more than 30 sounds to use. There are common ones like heavy rain, drippy rain, thunderstorms, but there are also uncommon sounds like fireworks or a mechanical keyboard, or even construction work.
Studies conducted by IBM in the 1970s and 1980s found that two or more mechanical keyboards typing away created noise that boosted productivity. Newspapers seem to have agreed. In 2014, the London Times piped in the sound of typewriters into their offices.
Silence seems to be a productivity killer. So does TV or lyrics with noise. Running a noise generator like this in the background may be just the thing you need.