Adding a sound to a frequency

Pure tones are effective and not always pleasant to sit with for an hour.

While a frequency is playing, tap the plus button. The app returns you to the sound library so you can pick something to layer on top. Choose your sound and it plays over the running frequency.

The navigation there feels abrupt right now, because the app drops you on the home screen with no explanation. It is working correctly. A clearer picker is on the roadmap.

Once you have both running, use the mixer to balance them. Most people want the frequency loud enough to feel and the sound loud enough to be pleasant, which usually means the sound sits higher in the mix than you would expect.