What are some alternatives?
When comparing Noisli and Defonic, you can also consider the following products
Noizio - Feeling that the noise of the big city is too much for you to bear?
A Soft Murmur - Ambient sounds to wash away distraction.
Krisp - Mute the background noise during your calls
Rainy Mood - Rainy Mood is the world's most popular rain simulator. Sleep, study, and relax with the sound of rain.
GitHub Audio - Tracks events across GitHub to generate calming work music
Aura Soundscape Player - Modern tools for modern applications.