I sufffer bad with getting to sleep and ive downloaded, installed, unistalled so many help relax/sleeping apps. The one i love and just got a new phone so i downloaded it straight away is rain sounds app.
Its not just rain sounds there is so many you can even add more rain, sea, birds fire, thunder ect
This helps me relax so quickly and sends me on my way to zzz land. Add a 2 hour timer or an hour, perfect.