Cadence sensors, heart rate monitor, accurate speed. I think apps on phones will get there eventually but not yet. You need ant + support on the phone. I doubt you'll get 8 hours with an app running locked to GPS. I run strava on my moto g in my jersey to track rides along with cheap computer to give me speed, cadence and distance in front of my face. With my last android phone I also had some issues with it overheating and spontaneously rebooting on rides with the app and GPS pushing the phones cpu for several hours combined with 90+ temp where I live