Calm.com has an app which I haven't tried, but you can preview the website from a browser to see if you want to try it. There's a free version of the app which I may try, but I wouldn't "upgrade" to the pay version, because it's a recurring "subscription," not a purchase.
I do like the website, which is free. I use it for calming background music at work more than I do for meditation, but it's good for both.