I have been using Endel app: https://apps.apple.com/ua/app/endel-focus-sleep-relax/id1346247457 https://apps.apple.com/ua/app/endel-focus-sleep-relax/id1346...

I have been using Endel app: https://apps.apple.com/ua/app/endel-focus-sleep-relax/id1346247457 https://apps.apple.com/ua/app/endel-focus-sleep-relax/id1346... in last 6 months. It has a procedural generated music. Depending on your task and bio rhythm it creates different beats. At least for me it works :-)