Hi, I am the founder of Noisli, a background noise and colour generator for working or relaxing, including also a text editor for distraction-free writing with Markdown support.
The web version (noisli.com) has been launched in Sept. 2013 and the service is now available also as universal iOS app, featuring a Timer and the ability to save your favourite sound combinations.
Noisli is mainly used as a concentration booster during work by developers, bloggers, writers, students, translators, and also by teachers during creative writing classes. It is also being used to relax during the day and as a sleeping aid by night, and used to help with hear damage recovery or Tinnitus.
Noisli