There are too many devices, smartphones and software combinations that can be used to follow gps tracks on a hike to cover here. I have used both a dedicated Garmin unit as well as my iPhone in this capacity. You can read about some of my conclusions here: The demise of the dedicated GPS, 1/9/16 For software, I use GaiaGPS. There is an Android version. I do recommend considering this app when making your own decision about what to use.
One small hint: to get a gpx file into or out of GaiaGPS, you email it!
GPS devices started out just able to indicate direction and distance to a set of GPS coordinates from the current location of the device. With products like GaiaGPS, the device is now able to show your current location on a map. If this map also includes the trail or gps track you wish to follow, then navigation becomes fairly simple. Assuming you can trust the map or the track.
Never rely solely on a GPS device. In addition to the danger of dead batteries, the device is only as good as the data it is presenting. If the data is wrong, the device is worse than useless. If you are new to this kind of device, practice with it on known trails. It can be hard to know what you are looking at the first times you try to locate yourself on the small screen of one of these devices.
Back in this tutorial to GPS Tracks