I used Smoothtrack for a couple weeks but my 2016 Iphone wasn't up to snuff. The battery would drain astonishingly fast and the phone itself was getting uncomfortably hot. I don't like phones so I don't want to invest in a new one. So instead, I bought the TRACKIR-5 kit and it works fantastic. I look like a dork with the IR "radar array" attached to the nerd headphones and even more like a Dweeb if I use the hat sensor instead and attach it to my Red Sox cap. I don't care about any of that really except I have forgotten the hat mounted device a couple of times and wore it to play tennis and once to the grocery store. Other than that, it was a breeze to setup and I haven't had to play around with the settings much. It'll be a game changer for me once I unlearn the 8-way hat. I continually forget and mix in the 8-way with head movement for a fine way to lose a target or just get discombobulated. I may undo the all the 8-way bindings except the 6 view and give that a try.