I did realise the one I use on Iphone is available on android: https://play.google.com/store/apps/details?id=com.spotlights...

Its not the same as my app with the frequency tones but it's a great app nonetheless.

If I built this in React Native I would have had you covered :( I am not aware of any Android apps doing the exact same thing. There are ofcourse tons of meditation apps tho so there could be similar.

But I found music is mostly added to other apps hence the reason to build my own. Do you use a Mac? I am contemplating to build it for Mac as well