I got this new app I really like called Lonofi. Basically, it's an ambient audio maker. They have a huge soundboard of noises, everything from dog sleds to magic brooms. You can listen to premade ambiance tracks or you can make your own. It's really cool because you can make ambiances based off of whatever chapter or panel your working on and listen to it while you work. I've been listening to a lot of rainy forest night sounds for mine!