Ummm, not really, it should have many ups and downs indicating sleep cycles.. where are you placing the phone? is your microphone working properly?
I looked it up and this is what it says “This is what a sleep graph will look like if the phone has trouble identifying your movements in bed. If you experience this, try repositioning your phone to make sure the microphone is directed towards the bed, or move the phone closer to your body if you’re using the accelerometer.” link: https://www.sleepcycle.com/how-sleep-cycle-works/
Dream Voices It's just for Android right now. The other ones out there are subscription based and are rip offs if you ask me. Good luck!