BangleApps/apps/berlinc/berlin-clock.js

// place your const, vars, functions or classes here
fields = [ 4 , 4 , 11 , 4 ];
width = g.getWidth();
height = g.getHeight();
rowHeight = height/4;
rowlights = [];

function drawBerlinClock() {
    var now = new Date();
    rowlights[0] = Math.floor(now.getHours() / 5);
    rowlights[1] = now.getHours() % 5;
    rowlights[2] = Math.floor(now.getMinutes() / 5);
    rowlights[3] = now.getMinutes() % 5;

    g.clear();

    g.drawRect(0,0,width,height);
    for (row = 0 ; row < 4 ; row++) {
      nfields = fields[row];
      boxWidth = width/nfields;

      for (col = 0 ; col < nfields ; col++) {
        x1 = col*boxWidth;
        y1 = row*rowHeight;
        x2 = (col+1)*boxWidth;
        y2 = (row+1)*rowHeight;

        g.setColor(1,1,1);
        g.drawRect(x1,y1,x2,y2);
        if (col<rowlights[row]) {

          if (row === 2 ) {
            if (((col+1) % 3) === 0) {
              g.setColor(1,0,0);
            } else {
              g.setColor(1,1,0);
            }
          } else {
              g.setColor(1,0,0);
          }

          g.fillRect(x1+2,y1+2,x2-2,y2-2);
        }
      }
    }
}

// special function to handle display switch on
Bangle.on('lcdPower', (on) => {
  g.clear();
  if (on) {
  	Bangle.drawWidgets();
  // call your app function here
  drawBerlinClock();
}});

// refesh every 15 sec
setInterval(drawBerlinClock, 15E3);

g.clear();
Bangle.loadWidgets();
Bangle.drawWidgets();
drawBerlinClock();
// Show launcher when middle button pressed
setWatch(Bangle.showLauncher, BTN2, {repeat:false,edge:"falling"});