I have the GT-50 clock/timer/thermometer in my airplane. I was installing new plexiglass in my plane and I wanted to get rid of the thermometer sticking thrrought the windshield. I always hated that probe sticking out, especially when installing a canopy cover. I also found the old thermometer dial difficult to read on the other side of the cockpit. I didn't care much for the old windup clock in the panel either. The GT-50 was the solution I came up with. I've had it now since 2013 and have been very pleased with it. I have a yoke mounted iPad running WingX. The timer in the GT-50 works great, but for me, the timers on the map page of WingX are easier to access. With that said, I still highly recommend the GT-50. It is a great addition to your panel. You can see it just above the yoke in the picture below.