I've been using the app for about an hour. The rain noise simulations are pretty relaxing. (They also have colored noise in the free version. Some colors are named but others are just their equivalents in hertz. For example green noise is 500hz) This is a better alternative than the ones that make you pay. The free version here gives you a bunch for free. The trial lets you test out premium sounds. I'm gonna test out how well it might help me sleep, tonight.

I've been listening to this site for about a decade and absolutely love it. It's made by a sound engineer who makes music, drones, white noise, field recordings, etc., sometimes with the cooperation of other artists. The site allows you to adjust a soundscape to your liking, and you can take individual audio tracks from multiple soundscapes to create your own composites, too.