Currently, buttons can be pushed to perform a variety of actions.
I just discovered that the only action causing a sound is one that plays one of several fixed sounds. I’d like to have an audio action that accepts a URL of a sound file. I don’t need all of the controls of the standard audio player – in fact, I find the standard player difficult to use on an actual smartphone. But in my case, all I want to do is tap a button to have a voice start counting seconds as part of an exercise app.