Alternative to settings menu?

One problem is you can't go back from the app settings to the settings menu.

You could maybe put the drawing code in a separate library file, like e.g. the weather app does, so you'd have something like this:

// apps/contourclock/lib.js
exports.drawClock = function(time, face) {
  // draw clockface [#face](https://forum.espruino.com/search/?q=%23face), at given time
}

// apps/contourclock/app.js
var face = Storage.readJSON('contourclock.json').face
setInterval(()=>require('contourclock').drawClock(new Date(), face), 60000);

// apps/contourclock/settings.js
(function(back) {
function preview(face) {
  require('contourclockclock').drawClock(new Date(), face);
}
// settings menu using preview() goes here
})

// apps.json
{
  "id": "contourclock"
"storage": [
      {"name":"contourclock.app.js","url":"app.js"},
      {"name":"contourclock","url":"lib.js"},
      {"name":"contourclock.settings.js","url":"settings.js"}
    ],
}