The tracking software is quite processor heavy so you will need a modern smartphone manufactured from 2019 onward. For iPhones you will need an iPhone6s or later. For Android the best way to check is to visit the
Google Play store link here. If you can download the app your phone is compatible. The Phone mount will hold phones with a width no narrower than 61mm and no wider than 77mm so you might have to remove bulky phone cases.