function draw_hud()
  local stop_app_label = 'edit'
  button(ui_state, stop_app_label, {x=5, y=Safe_height-10-Line_height-10,
    w=5+App.width(stop_app_label)+5, h=5+Line_height+5,
    bg=Menu_background,
    icon = function(p)
      App.color(Normal_color)
      rect('line', p.x,p.y, p.w,p.h)
      g.print(stop_app_label, p.x+5, p.y+5)
    end,
    onpress1 = stop_app,
  })
  color(0.5, 0.5, 0.5)
  for _,touch_id in ipairs(touches()) do
    local x,y = touch(touch_id)
    circle('fill', x,y, 10)
  end
end